The Collaborative International Dictionary of English v.0.48:

Soybean \Soy"bean\ (soi"b[=e]n`), n.
   1. (Bot.) An Asiatic leguminous herb (Glycine max, formerly
      Glycine Soja) the seeds of which (also called soy
      beans) are used in preparing the sauce called soy.
      Called also soya bean and soya.
      [1913 Webster]

   2. the seeds of the Glycine max, which produce soybean
      oil; -- called also soya bean.
      [PJC]

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]

The Collaborative International Dictionary of English v.0.48:

Soja \So"ja\ (s[=o]"j[.a] or s[=o]"y[.a]), n. (Bot.)
   An Asiatic leguminous herb (Glycine max, formerly Glycine
   Soja) the seeds of which (called soy beans) are used in
   preparing the sauce called soy. Called also soya.
   [1913 Webster]

WordNet (r) 3.0 (2006):

Glycine max
    n 1: erect bushy hairy annual herb having trifoliate leaves and
         purple to pink flowers; extensively cultivated for food and
         forage and soil improvement but especially for its
         nutritious oil-rich seeds; native to Asia [syn: soy,
         soya, soybean, soya bean, soybean plant, soja,
         soja bean, Glycine max]