Webster's Revised Unabridged Dictionary -- Volume C

-- Crab louse (Zoöl.), a species of louse (Phthirius pubis), sometimes infesting the human body.

-- Crab plover (Zoöl.), an Asiatic plover (Dromas ardeola).

-- Crab's eyes, or Crab's stones, masses of calcareous matter found, at certain seasons of the year, on either side of the stomach of the European crawfishes, and formerly used in medicine for absorbent and antacid purposes; the gastroliths.

-- Crab spider (Zoöl.), one of a group of spiders (Laterigradæ); -- called because they can run backwards or sideways like a crab.

-- Crab tree, the tree that bears crab applies.

-- Crab wood, a light cabinet wood obtained in Guiana, which takes a high polish. McElrath.

-- To catch a crab (Naut.), a phrase used of a rower: (a) when he fails to raise his oar clear of the water; (b) when he misses the water altogether in making a stroke.

Crab (krăb), v. t.

1. To make sour or morose; to embitter. [Obs.]

Sickness sours or crabs our nature.
Glanvill.

2. To beat with a crabstick. [Obs.] J. Fletcher.

Crab, v. i. (Naut.)To drift sidewise or to leeward, as a vessel. Ham. Nav. Encyc.

Crab, a. [Prob. from the same root as crab, n.] Sour; rough; austere.

The crab vintage of the neighb'ring coast.
Dryden.