noun Download 🔗Share Any of various transparent marine hydrozoans, of the order Siphonophorae, that float or swim as colonies of polyps. Examples : "While snorkeling, we saw a long, delicate siphonophore floating near the surface; it looked like a single creature, but was actually a colony of tiny, individual animals working together. " organism animal ocean biology nature Chat with AIVocabulary GamePractice Reading