gaffer vs old geezer

gaffer and old geezer both are nouns.

Word	Noun	Adjective	Verb	Adverb
gaffer	Yes	No	No	No
old geezer	Yes	No	No	No

As nouns, gaffer and old geezer are synonyms defined as:

Other synonyms of gaffer include antique, old-timer, oldtimer.

gaffer (noun)	old geezer (noun)
a person who exercises control over workers	an elderly man
an elderly man
an electrician responsible for lighting on a movie or tv set