knock off

get rid of (someone who may be a threat) by killing; "The mafia liquidated the informer"; "the double agent was neutralized"

cut the price of

take by theft; "Someone snitched my wallet!"

write quickly; "She dashed off a note to her husband saying she would not be home for supper"; "He scratched off a thank-you note to the hostess"

stop pursuing or acting; "drop a lawsuit"; "knock it off!"