knock something on the head
US /nɑk ˈsʌm.θɪŋ ɑn ðə hɛd/
UK /nɑk ˈsʌm.θɪŋ ɑn ðə hɛd/
1.
to stop doing something or to put an end to a plan or activity
:
•
We need to knock this project on the head before it costs us any more money.
•
I decided to knock my plans on the head and stay home instead.