display vs show off

display is a noun but show off is not a noun.

Word	Noun	Adjective	Verb	Adverb
display	Yes	No	Yes	No
show off	No	No	Yes	No

As verbs, show off is a hyponym of display; that is, show off is a word with a more specific, narrower meaning than display:

display (noun)	show off (noun)
something shown to the public
a visual representation of something
an electronic device that represents information in visual form
exhibiting openly in public view
something intended to communicate a particular impression
behavior that makes your feelings public

display (verb)	show off (verb)
to show, make visible or apparent	display proudly; act ostentatiously or pretentiously
attract attention by displaying some body part or posing; of animals