(krab) noun
1. Any of various species of ten-footed crustaceans of the suborder Brachyura in the order Decapoda, characterized by a small abdomen folded under the body, a flattened carapace, and short antennae. They can walk in any direction without turning, but usually move sideways.
2. The hermit crab.
3. The horseshoe crab.
4. A crab louse, Phthirus pubis.
5. Aeron. The lateral slant in an airplane needed to maintain a flight line in a cross-wind.
6. A form of windlass.
7. plural The lowest throw of a pair of dice.
—to catch a crab. In rowing, to sink an oar blade too deeply; also, to miss the water entirely or skim the surface in making a stroke, and thus fall backward.
—v. crabbed, crab·bing v.i.
1. To take or fish for crabs.
2. U.S. Colloq. To back out: to crab out of an agreement.
3. Naut. To drift sideways, as a ship.
—v.t.
4. Aeron. To head (an airplane) across a contrary wind so as to compensate for drift. [OE crabba. Akin to CRAB³]

(krab) noun
1. A crab apple.
2. A crab-apple tree.
3. An ill-tempered, surly, or querulous person.
—v. crabbed, crab·bing v.t.
1. Colloq. To disparage; belittle; complain about.
2. Colloq. To ruin or spoil: He crabbed the entire act.
3. Obs. To make surly or sour; irritate.
4. Brit. Dial. To cudgel or beat, as with a crabstick.
—v.i.
5. To be ill-tempered. [? <Scand. Cf. dial. Sw. scrabba wild apple.]

(krab) v.i. crabbed, crab·bing
To seize each other fiercely, as hawks when fighting; claw. [<MDu. crabben scratch. Akin to CRAB¹.]

A constellation and sign of the Zodiac; Cancer.