Define nymph. nymph synonyms, nymph pronunciation, nymph translation, English dictionary definition of nymph. n. 1. Greek & Roman Mythology Any of numerous minor deities represented as beautiful maidens inhabiting and sometimes personifying features of nature such... Nymph (biology) Two Schistocerca gregaria nymphs beside an adult In biology, a nymph (from Ancient Greek νύμφα nūmphē meaning "bride") is the juvenile form of some invertebrates, particularly insects, which undergoes gradual metamorphosis (hemimetabolism) before reaching its adult stage. [1] The meaning of NYMPH is any of the minor divinities of nature in classical mythology represented as beautiful maidens dwelling in the mountains, forests, trees, and waters. Nymph can mean a young woman in ancient stories, or a form of an insect that has not yet developed into an adult. Learn more about the word, its pronunciation, and its usage in sentences.