From The Collaborative International Dictionary of English v.0.48 :
Patty \Pat"ty\, n.; pl. Patties. [F. p[^a]t['e]. See Pasty.]
A little pie.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
patty
n 1: small flat mass of chopped food [syn: patty, cake]
2: small pie or pasty
3: round flat candy