"soy," 1670s; see soy. Soyaburger is attested from 1953.
Entries linking to soya
soy n.
1670s, saio "soybean-based Asian fish sauce," from Dutch soya, from Japanese soyu, variant of shoyu "soy," from Chinese shi-yu, from shi "fermented soy beans" + yu "oil." Etymology reflects Dutch presence in Japan before English and American merchants began to trade there.