oldtimer vs gaffer

oldtimer and gaffer both are nouns.

Word	Noun	Adjective	Verb	Adverb
oldtimer	Yes	No	No	No
gaffer	Yes	No	No	No

As nouns, oldtimer and gaffer are synonyms defined as:

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

oldtimer (noun)	gaffer (noun)
an elderly man	a person who exercises control over workers
an experienced person who has been through many battles; someone who has given long service	an elderly man
	an electrician responsible for lighting on a movie or tv set