From Longman Dictionary of Contemporary Englishldoce_173_bjellyfishjel‧ly‧fish /ˈdʒelifɪʃ/ noun (plural jellyfish) [countable] 
HBAa sea animal that has a round transparent body and can sting you
HBAa sea animal that has a round transparent body and can sting youExamples from the Corpus
jellyfish• These species float near the surface of the water on their feathery extended tentacles and hunt jellyfish.• But afraid of the stinging jellyfish that shimmered, ghostlike, underneath the surface, I never even tried.• After an hour, my hands turned limp, like free-swimming jellyfish puckered in little wrinkles and folds along the fingertips.• Those waters remained the domain of the jellyfish and other floating invertebrates.• There they give just the same protection to their new owners as they did to the jellyfish that developed them.• I can feel myself dissolving where the jellyfish stings me.• Though not as deadly as the sea wasp, this jellyfish can cause severe irritation if it stings a human.• Tofu by texture is what jellyfish are made of, all soft and squishy and unearthly. 