Nouns

(n)crabdecapod having eyes on short stalks and a broad flattened carapace with a small abdomen folded under the thorax and pincers
(n)crab, crabby persona quarrelsome grouch
(n)crab, crabmeatthe edible flesh of any of various crabs
(n)crab louse, pubic louse, crab, Phthirius pubis, Pthirus pubisa louse that infests the pubic region of the human body
(n)craba stroke of the oar that either misses the water or digs too deeply“he caught a crab and lost the race”

Verbs

(v)crabdirect (an aircraft) into a crosswind
(v)crabscurry sideways like a crab
(v)crabfish for crab
(v)gripe, bitch, grouse, crab, beef, squawk, bellyache, hollercomplain“What was he hollering about?”