rain frog noun 9forms 1 noun9 •Any of many species of frogs in diverse genera. •Those of family Brevicepitidae, of Africa •Those of family Eleutherodactylidae, of the Americas •Austrochaperina pluvialis (family Microhylidae), of Australia •Craugastor (Craugastoridae), of the Neotropics •Leptodactylus (family Leptodactylidae), of the Neotropics •Pristimantis (family Strabomantidae), of the Neotropics •Scaphiophryne (family Microhylidae), of Madagascar •(US) A tree frog, especially, a spring peeper. formsrain frogs