stave vs stave in

stave is a noun but stave in is not a noun.

Word	Noun	Adjective	Verb	Adverb
stave	Yes	No	Yes	No
stave in	No	No	Yes	No

As verbs, stave and stave in are synonyms defined as:

stave (noun)	stave in (noun)
one of several thin slats of wood forming the sides of a barrel or bucket
a crosspiece between the legs of a chair
(music) the system of five horizontal lines on which the musical notes are written

stave (verb)	stave in (verb)
burst or force (a hole) into something	burst or force (a hole) into something
furnish with staves	break in the staves (of)