abut vs butt on

abut and butt on both are verbs.

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

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

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

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