knock on the head

English

knock on the head (third-person singular simple present knocks on the head, present participle knocking on the head, simple past and past participle knocked on the head)

(transitive) To put an end to; to defeat or frustrate (a scheme or project).
- 1887, Harriet W. Daly, Digging, Squatting, and Pioneering Life in the Northern Territory of South Australia, page 46:
  My young brothers and sisters looked very awestruck at this first glimpse of barbaric life, and I fear many of the theories they had formed about going into the wilds alone, and experiencing some Robinson Crusoe-like adventures, were suddenly "knocked on the head," to use a forcible colonial expression, one, however, which rather pointed to their probable fate if they had attempted anything of the kind.
- 2020 August 26, Tim Dunn, “Great railway bores of our time!”, in Rail, page 46:
  The urban myth of the sun shining through Box Tunnel on Brunel's birthday may have been knocked on the head, but in its portal facing designs he created structures which have stood the test of time well.