a tendril or clasper.-a soft tactile appendage of the mantle of many mollusca, and of the parapodia of annelida. those near the head of annelids are tentacular cirri; those of the last segment are caudal cirri.-the jointed, leglike organs of cirripedia. see annelida, and polychaeta.-the external male organ of trematodes and some other worms, and of certain mollusca.-see under cloud.