butt on vs abut

butt on and abut both are verbs.

Word	Noun	Adjective	Verb	Adverb
butt on	No	No	Yes	No
abut	No	No	Yes	No

As verbs, butt on and abut are synonyms defined as:

Other synonyms of butt on include adjoin, border, butt, butt against, edge, march.

butt on (verb)	abut (verb)
lie adjacent to another or share a boundary	lie adjacent to another or share a boundary