O O

O.K O.K.

OAF oaf · oafish

OAK oak · oak-apple · oak-mast · oakum

OAR oar · oarsman

OAS oasis · oast

OAT oat · oat-cake · oaten · oat-grass · oath · oatmeal

OBD obduracy · obdurate

OBE obedience · obedient · obeisance · obelisk · obelus · obese · obesity · obey

OBF obfuscate

OBI obiter · obituary

OBJ object · object-glass · objection · objectionable · objective · objectivity · object-lesson · objector · object-slide · objurgate · objurgation

OBL Oblate · oblation · obligation · obligatory · oblige · obliging · obligingness · oblique · obliterate · obliteration · oblivion · oblivious · oblong · obloquy

OBN obnoxious

OBO oboe · oboist

OBS obscene · obscenity · obscurantism · obscurantist · obscuration · obscure · obscurity · obsequies · obsequious · obsequiousness · observable · observance · observant · observation · observatory · observe · observer · observing · obsess · obsession · obsidian · obsolescent · obsolete · obstacle · obstetric · obstetrician · obstetrics · obstinacy · obstinate · obstreperous · obstruct · obstruction · obstructive

OBT obtain · obtainable · obtrude · obtrusion · obtrusive · obtrusiveness · obturate · obturation · obturator · obtuse · obtuse-angled

OBV obverse · obviate · obvious · obviousness

OCC occasion · occasional · occident · occidental · occipital · occiput · occlude · occlusion · occult · occultation · occultism · occupancy · occupant · occupation · occupational · occupier · occupy · occur · occurrence

OCE ocean · ocean-going · Oceania · oceanic · ocean-lane · oceanography · ocellus · ocelot

OCH ochre

OCL o'clock

OCT octagon · octagonal · octahedral · octahedron · octave · Octavian · octavo · octet · October · octogenarian · octopus · octosyllabic · octuple

OCU ocular · oculist

ODD odd · oddity · oddments · oddness · odds

ODE ode

ODI odious · odiousness · odium

ODO odometer · odoriferous · odorous · odour · odourless

ODY Odysseus · Odyssey

OEC oecumenical

OED oedema · Oedipus

OEN oenometer

OER o'er

OES oesophagus · oestrus

OF of

OFF off · off(-)shore · offal · Offaly · offence · offend · offender · offending · offensive · offer · offering · offertory · off-hand · off-handed · off-handedness · office · office-boy · officer · office-work · official · officialdom · officialese · officiate · officinal · officious · officiousness · offing · off-print · offset · offshoot · offspring · off-the-record

OFT oft · often · oft-times

OGE ogee

OGH ogham

OGI ogival · ogive

OGL ogle

OGR ogre

OH oh

OHM ohm · ohmmeter

OID oidium

OIL oil · oil up · oil-bath · oil-bearing · oilcake · oil-can · oil-cloth · oil-colour · oil-cruet · oiled · oil-engine · oiler · oil-field · oil-fired · oil-gauge · oil-groove · oil-hole · oiliness · oiling · oil-lamp · oilman · oil-merchant · oil-paint · oil-painting · oil-producing · oil-rig · oil-ring · oil-shop · oilskin · oilstone · oil-stove · oil-tracks · oil-varnish · oil-well · oil-works · oily

OIN ointment

OKA okapi

OLD old · old-clothes-man · old-clothes-shop · old-clothes-woman · olden · old-established · old-fashioned · oldish · old-maidish · old-world

OLE oleaginous · oleander · oleiferous · oleograph

OLF olfactive

OLI oligarchic · oligarchy · olio · olivaceous · olive · olive-branch · olive-green · olive-grove · olive-grower · olive-moulding · olive-oil · Oliver

OLL olla podrida

OLY olympiad · Olympian · Olympic · Olympus

OMA Omagh · Oman

OME omega · omelet · omen

OMI ominous · omission · omit

OMN omnibus · omnipotence · omnipotent · omnipresence · omnipresent · omniscience · omniscient · omnivorous

ON on

ONA onager

ONC once · once-over · on-coming

ONE one · one-armed · one-celled · one-cylinder · one-eyed · one-horse · one-legged · one-price · oner · onerous · oneself · one-sided · one-storied · one-way

ONI onion · onion skin · onion-sauce

ONL onlooker · only

ONO onomatopoeia · onomatopoeic

ONR onrush

ONS onset · onshore · onslaught

ONT onto · ontogenesis · ontological · ontology

ONU onus

ONW onward · onwards

ONY onyx

OOL oolite · oolitic

OOZ ooze · oozing

OPA opacity · opal · opalescence · opalescent · opaque · opaqueness

OPE open · open out · open up · open-air · opener · open-eyed · open-faced · open-handed · open-handedness · open-hearted · opening · open-minded · open-mouthed · open-necked · opera · operable · opera-cloak · opera-glasses · opera-hat · opera-house · operate · operatic · operating-lever · operating-table · operating-theatre · operation · operative · operator · operculum · operetta

OPH ophidia · ophidian · ophite · ophthalmia · ophthalmic · ophthalmologist · ophthalmology · ophthalmoscope

OPI opiate · opine · opinion · opinionated · opium · opium-den · opium-fiend · opium-smoker

OPO opodeldoc · opossum

OPP opponent · opportune · opportuneness · opportunism · opportunist · opportunity · oppose · opposed · opposer · opposing · opposite · opposition · oppress · oppression · oppressive · oppressiveness · oppressor · opprobrious · opprobrium

OPT opt · optative · optic · optical · optician · optics · optimism · optimist · optimistic · option · optional

OPU opulence · opus · opuscule

OR or

ORA orach · oracle · oracular · oral · orange · orange-blossom · orange-flower · orange-house · orange-lily · orangeman · orangery · orange-stick · orangism · orang-utang · orate · oration · orator · oratorical · oratorio · oratory

ORB orb · orbit

ORC orc · orchard · orchestra · orchestral · orchestrate · orchestration · orchid

ORD ordain · ordeal · order · order about · order in · order off · order out · order-book · orderliness · orderly · ordinal · ordinance · ordinary · ordinate · ordination · ordnance · ordure

ORE ore · oread

ORG organ · organ-blower · organ-builder · organ-case · organdi · organ-grinder · organic · organism · organist · organization · organize · organizer · organ-loft · organ-pipe · organ-screen · organ-stop · orgasm · orgiac · orgy

ORI oriel · orielled · orient · oriental · orientate · orientation · orienteering · orifice · origin · original · originality · originate · origination · originator · oriole · Orion · orison

ORK Orkneys (the)

ORL orlon · orlop

ORM ormulu

ORN ornament · ornamental · ornamentation · ornate · ornithological · ornithologist · ornithology · ornithorhynchus

ORO orography · orotund

ORP orphan · orphanage · orphaned · Orpheus · orpiment

ORR orrery · orris

ORT orthocentre · orthocromatic · orthodox · orthodoxy · orthogonal · orthographic · orthography · orthopaedic · orthopaedist · orthopaedy · ortolan

OSC oscillate · oscillating · oscillation · oscillator · oscillatory · osculate · osculation · osculatory

OSI osier · osier-bed

OSL Oslo

OSM Osmanli · osmium · osmosis · osmotic

OSP osprey

OSS osseous · Ossian · Ossianic · ossicle · ossification · ossify · Ossory · ossuary

OST ostensible · ostensory · ostentation · ostentatious · osteology · osteomalacia · osteopath · osteopathy · ostler · ostracism · ostracize · ostreiculture · ostrich · ostrich-feather · ostrich-plume

OTA otalgia

OTH other · otherwise · otherworldly

OTI otic · otiose

OTO otology · otoscope

OTT otter · Otto · Ottoman

OUG ought

OUN ounce

OUR our · ours · ourself · ourselves

OUS oust

OUT out · out and out · outbid · outboard · out-bound · outbreak · out-building · outburst · outcast · outcaste · outclass · outcome · outcrop · outcry · outdistance · outdo · outdoor · outdoors · outer · outermost · outface · outfall · outfit · outfitter · outfitting · outflank · outflow · outgeneral · outgoing · outgrow · outgrowth · out-guard · outhouse · outing · outlandish · outlast · outlaw · outlawry · outlay · outlet · outline · outlive · outlook · outlying · outmanoeuvre · outmarch · outmost · outnumber · out-of-date · out-of-school · out-of-the-way · outpace · out-patient · out-post · outpouring · output · outrage · outrageous · outrageousness · outrange · outré · outreach · outride · outrider · outrigger · outright · outrun · outset · outshine · outside · outsider · outsize · outskirts · outspan · outspoken · outspokenness · outspread · outstanding · outstare · outstay · outstretched · outstrip · outvie · outward · outward-bound · outwards · outwear · outweigh · outwit · outwork · outworker

OUZ ouzel

OVA oval · ovalize · ovary · ovate · ovation

OVE oven · over · overact · overall · over-all · overarm · overawe · overbalance · overbear · overbearing · overbid · overboard · overbold · overburden · overcapitalization · overcast · overcharge · overcloud · overcoat · overcome · over-confidence · over-confident · overcrowd · overcrowded · overcrowding · over-develop · overdo · overdose · overdraft · overdraw · overdress · overdrive · overdue · overeat · over-elaborate · over-estimate · overexcite · overexcitement · overexertion · over-expose · over-exposure · over-familiar · over-fatigue · overfed · overfeed · overflow · overflowing · overfree · overgarment · overgrow · overgrown · overgrowth · overhang · overhaul · overhead · overhear · overheat · overheated · overhung · over-indulge · over-indulgence · overjoyed · overladen · overland · overlap · overlapping · overlay · overleaf · overlie · overload · overlook · overlord · overlordship · overmantel · overmaster · overmastering · overmuch · over-nice · overnight · over-paint · overpass · overpayment · overplus · over-populated · overpower · over-powering · overpraise · over-print · overproduction · over-proof · overrate · overreach · over-refinement · override · overriding · over-ripe · overrule · overrun · oversea · overseas · oversee · overseer · overset · oversew · overshadow · overshoe · overshoot · overshot · oversight · oversize · oversleep · oversleeve · overspread · overstate · overstatement · overstay · overstep · overstock · overstrain · overstress · overstrung · overt · overtake · overtaking · overtax · overthrow · overtime · overtone · overtop · over-train · over-trick · overtrump · overtrumping · overture · overturn · overvaluation · overvalue · overvoltage · overweening · overweight · overwhelm · overwhelming · overwork · overwrought · over-zealous

OVI ovibos · Ovid · oviform · ovine · oviparous

OVO ovoid · ovolo

OVU ovule · ovum

OWE owe

OWI owing

OWL owl · owlet · owlet-moth · owlish

OWN own · owner · ownership

OX ox

OXA oxalate · oxalic

OXC ox-cart

OXE ox-eye

OXH ox-hide

OXI oxidation · oxide · oxidizable · oxidize · oxidizer

OXT ox-tail · ox-tongue

OXY oxyacetylene · oxygen · oxygenate · oxyhydrogen · oxytone

OYE oyes! oyez!

OYS oyster · oyster-bed · oyster-breeder · oyster-breeding · oyster-catcher · oyster-dealer · oyster-farm · oyster-farming · oyster-knife · oyster-shell

OZO ozocerite · ozone · ozonization · ozonize · ozonizer