one of the brachyuran crustacea. they are mostly marine, and usually have a broad, short body, covered with a strong shell or carapace. the abdomen is small and curled up beneath the body.-the zodiacal constellation cancer.-a crab apple; -- so named from its harsh taste.-a cudgel made of the wood of the crab tree; a crabstick.-a movable winch or windlass with powerful gearing, used with derricks, etc.-a form of windlass, or geared capstan, for hauling ships into dock, etc.-a machine used in ropewalks to stretch the yarn.-a claw for anchoring a portable machine.-to make sour or morose; to embitter.-to beat with a crabstick.-to drift sidewise or to leeward, as a vessel.-sour; rough; austere.