A female gamete; an ovum. Also called egg cell. The round or oval female reproductive body of various animals, including birds, reptiles, amphibians, fishes, and insects, consisting usually of an embryo surrounded by nutrient material and a protective covering. The oval, thin-shelled reproductive body of a bird, especially that of a hen, used as food. Something having the ovoid shape of an egg. Slang A fellow; a person: He's a good egg. To cover with beaten egg, as in cooking. Slang To throw eggs at. egg on (one's) face Informal Embarrassment; humiliation: If you do that, you'll end up with egg on your face. lay an egg Informal To fail, especially in a public performance. put Informal To risk everything on a single venture. To encourage or incite to action. Used with on: The racing fans egged their favorites on.