The Collaborative International Dictionary of English v.0.48:
Sea grape \Sea" grape`\ 1. (Bot.) (a) The gulf weed. See under Gulf. (b) A shrubby plant (Coccoloba uvifera) growing on the sandy shores of tropical America, somewhat resembling the grapevine. [1913 Webster] 2. pl. (Zool.) The clusters of gelatinous egg capsules of a squid (Loligo). [1913 Webster]