bump vs bump off

bump is a noun but bump off is not a noun.

Word	Noun	Adjective	Verb	Adverb
bump	Yes	No	Yes	No
bump off	No	No	Yes	No

bump (noun)	bump off (noun)
an impact (as from a collision)
something that bulges out or is protuberant or projects from its surroundings
a lump on the body caused by a blow

bump (verb)	bump off (verb)
knock against with force or violence	kill intentionally and with premeditation
remove or force from a position of dwelling previously occupied
to play music at loud volume
to enjoy some music greatly
dance erotically or dance with the pelvis thrust forward
come upon, as if by accident; meet with
assign to a lower position; reduce in rank