stop (one's) clock
dated To kill one; to limit the amount of time one has left in one's life. One would expect him to be resentful to have a disease stop his clock at such a young age, but Jacob remains in good spirits and optimistic about finding a cure.
stop someone's clock
Kill someone, as in They threatened to stop his clock if he appeared on the witness stand. This expression transfers the ticking of a clock to the progress of one's life. [Slang; 1940s]