food grown from seed: the plain plant diet (vegetables and grains) Daniel asked for in place of the king's rich food
This word appears only twice in the whole Bible, both times in the opening chapter of Daniel, where Daniel and his friends ask to be fed it instead of the king's food and wine. The two verses spell it a little differently, but they mean the same thing: food that is grown from seed. It is a broad word, covering vegetables, grains, and beans alike, not one narrow kind of food.
The familiar King James rendering "pulse" (beans and lentils) is narrower than the Hebrew. It comes from the ancient Greek and Latin translations, which guessed at legumes; the Hebrew itself only says "things grown from seed." Modern translations return to "vegetables," which is closer to what the word actually means.
The word's force in the story is the contrast it draws. Set against the king's lavish provision, this seed-food is plain, humble, and comes straight from the ground God made to bear seed. There is even a quiet play on words: Daniel and his companions are introduced as young men "of the royal seed" (זֶרַע), and now these "seed" youths ask for "seed-food." The point is that their life and health come from God's simple provision, not from the king's table.