The Collaborative International Dictionary of English v.0.48:

Soybean oil \Soy"bean oil\ (soi"b[=e]n` oil), n.
   an oil obtained from the soybean (Glycine max), rich in
   protein, fats, sterols, and phospholipids, used as a food and
   in paints and varnishes and in various industrial
   applications; -- called also soya oil. It is also used in
   preparing the sauce called soy or soy sauce.
   [PJC]

WordNet (r) 3.0 (2006):

soy sauce
    n 1: thin sauce made of fermented soy beans [syn: soy sauce,
         soy]