late 14c., "peevish, angry, ill-tempered, spiteful," also "vicious, wicked, perverse," from crab (n.1), from the crab's combative disposition; mid-15c. as "moving backwards" and in reference to crookedness. Of taste "bitter, harsh," late 14c., from crab (n.2). Related: Crabbedly; crabbedness.
updated on April 27, 2018