The Collaborative International Dictionary of English v.0.48:

french fries \french fries\ french-fried potatoes \french-fried
potatoes\ n. pl.
   Strips of potatoes, usually cut with a rectangular
   cross-section, cooked by immersing in hot fat or oil.
   [PJC]

WordNet (r) 3.0 (2006):

french fries
    n 1: strips of potato fried in deep fat [syn: french fries,
         french-fried potatoes, fries, chips]