shut up vs lock in

shut up is an adjective but lock in is not an adjective.

Word	Noun	Adjective	Verb	Adverb
shut up	No	Yes	Yes	No
lock in	No	No	Yes	No

As verbs, shut up and lock in are synonyms defined as:

shut up and lock in: place in a place where something cannot be removed or someone cannot escape

Other synonyms of shut up include lock, lock away, lock up, put away, shut away.

shut up (adjective)	lock in (adjective)
closely confined

shut up (verb)	lock in (verb)
cause to be quiet or not talk	place in a place where something cannot be removed or someone cannot escape
refuse to talk or stop talking; fall silent	close with or as if with a tight seal
place in a place where something cannot be removed or someone cannot escape