Hatch2  —v. 1 a (often foll. By out) (of a young bird or fish etc.) Emerge from the egg. B (of an egg) produce a young animal. 2 incubate (an egg). 3 (also foll. By up) devise (a plot etc.). —n. 1 act of hatching. 2 brood hatched. [earlier hacche, from germanic]