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):

soja
    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]