break in vs butt in

break in and butt in both are verbs.

Word	Noun	Adjective	Verb	Adverb
break in	No	No	Yes	No
butt in	No	No	Yes	No

As verbs, break in and butt in are synonyms defined as:

Other synonyms of break in include barge in, chime in, chisel in, cut in, put in.

break in (verb)	butt in (verb)
make submissive, obedient, or useful	break into a conversation
break so as to fall inward
start in a certain activity, enterprise, or role
break into a conversation
intrude on uninvited
enter someone's (virtual or real) property in an unauthorized manner, usually with the intent to steal or commit a violent act