put head on the block

put (one's) head on the block

To assume or expose oneself to some risk, danger, or responsibility; to imperil oneself or put oneself in harm's way; to risk damaging one's reputation as the result of doing something. Look, I'm putting my head on the block for you here. I could get fired if they find out what we're up to! You have to take some risks to be successful in business and in life, but don't put your head on the block for no good reason.
See also: block, head, on, put
Farlex Dictionary of Idioms.

put one's head on the block (for someone or something)

Fig. to take great risks for someone or something; to go to a lot of trouble or difficulty for someone or something; to attempt to gain favor for someone or something. I don't know why I should put my head on the block for Joan. What has she ever done for me? Sally tried to get me to put in a good word about her with the boss. But the last time I put my head on the block for anyone, it all backfired, and when the person goofed up, I looked like an idiot!
See also: block, head, on, put
McGraw-Hill Dictionary of American Idioms and Phrasal Verbs.

put/lay your head/neck on the block

risk defeat, failure, etc.; put yourself in a situation where you might be blamed, criticized, etc: The government laid its head on the block and said that if it loses this vote in Parliament tonight it will call an election. I’m prepared to put my neck on the block and promise that the new building will be ready by the end of the year.In the past when people were executed (= killed as a punishment), they had to lay their head on a block so that it could be chopped off.
See also: block, head, lay, neck, on, put
Farlex Partner Idioms Dictionary
See also:
  • put (one's) head on the block
  • put (one's) neck on the block
  • put your head on the block
  • lay (one's) head on the block
  • lay (one's) neck on the block
  • put/lay your head/neck on the block
  • put (one's) butt on the line
  • put yourself on the line
  • put (oneself) on the line