old-timer vs old geezer

old-timer and old geezer both are nouns.

Word	Noun	Adjective	Verb	Adverb
old-timer	Yes	No	No	No
old geezer	Yes	No	No	No

As nouns, old-timer and old geezer are synonyms defined as:

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

old-timer (noun)	old geezer (noun)
an elderly man	an elderly man
an experienced person who has been through many battles; someone who has given long service