Yes, soy is a Scrabble word!

Noun

1. A source of oil; used for forage and soil improvement and as food

2. 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

3. Thin sauce made of fermented soy beans

4. The most highly proteinaceous vegetable known; the fruit of the soybean plant is used in a variety of foods and as fodder (especially as a replacement for animal protein)