·adj In a vague sense, resembling seaweeds, or of the nature of seaweeds.
II. Fucoid ·noun A plant, whether recent or fossil, which resembles a seaweed. ·see Fucoid, ·adj.
III. Fucoid ·adj Properly, belonging to an order of alga: (Fucoideae) which are blackish in color, and produce oospores which are not fertilized until they have escaped from the conceptacle. The common rockweeds and the gulfweed (Sargassum) are fucoid in character.