[1] : The Collaborative International Dictionary of English v.0.48

geezer \gee"zer\, n. dial. corrupt. of guiser a mummer.
   a queer old fellow; an old chap; sometimes, an old woman.
   contemptuous, slang.

   syn: bloke.
        webster 1913 suppl.
see also:
guiser 

[2] : WordNet (r) 2.0

geezer
     n : a man who is usually old and/or eccentric syn: bloke
see also:
bloke 

[3] : Moby Thesaurus II by Grady Ward, 1.0

36 moby thesaurus words for "geezer":
   father time, methuselah, nestor, old paar, centenarian, dotard,
   elder, gaffer, golden-ager, gramps, grandfather, grandsire,
   graybeard, nonagenarian, octogenarian, old chap, old codger,
   old dog, old duffer, old geezer, old gent, old gentleman, old man,
   old party, old-timer, older, oldster, pantaloon, patriarch,
   presbyter, senior citizen, septuagenarian, sexagenarian,
   the quiet-voiced elders, venerable sir, veteran

Geezer >> G Words
Geezer, definition of term: Geezer
geezer_pag1.html

Old Geezer >> O Words
Old Geezer, definition of term: Old Geezer
old+geezer_pag1.html