knock off vs do in

knock off and do in both are verbs.

Word	Noun	Adjective	Verb	Adverb
knock off	No	No	Yes	No
do in	No	No	Yes	No

As verbs, knock off and do in are synonyms defined as:

knock off and do in: get rid of (someone who may be a threat) by killing

Other synonyms of knock off include liquidate, neutralise, neutralize, waste.

knock off (verb)	do in (verb)
stop pursuing or acting	get rid of (someone who may be a threat) by killing
get rid of (someone who may be a threat) by killing
write quickly
take by theft
cut the price of