Merriam-Webster Collegiate Dictionary - spawn

 I. verb  Etymology: Middle English, from Anglo-French espandre to spread out, shed, scatter, ~, from Latin expandere to expand  Date: 15th century  intransitive verb  1. to deposit or fertilize ~  2. to produce young especially in large numbers  transitive verb  1.  a. to produce or deposit (eggs) — used of an aquatic animal  b. to induce (fish) to ~  c. to plant with mushroom ~  2. bring forth, generate the idea ~ed controversy  • ~er noun  II. noun  Date: 15th century  1. the eggs of aquatic animals (as fishes or oysters) that lay many small eggs  2. product, offspring; also offspring in great numbers  3. the seed, germ, or source of something  4. mycelium especially prepared (as in bricks) for propagating mushrooms