Pronunciation: ( jel'ē-fish"),[key] —n., —pl.(esp. collectively)-fish,(esp. referring to two or more kinds or species)-fish•es. 1. any of various marine coelenterates of a soft, gelatinous structure, esp. one with an umbrellalike body and long, trailing tentacles; medusa.
2. Informal.a person without strong resolve or stamina; an indecisive or weak person.