Crabby.

Little nipper.

Dear Word Detective: Why is being in a cross or bad mood referred to as being “crabby”? Are crabs naturally irritable? Who makes this stuff up? — Charles.

Well, to answer your third question first, you do. More precisely, we all do. The English language, like all human languages, is a group effort, the product of a committee consisting of everyone who has ever spoken it (and a good number of folks who have spoken other languages as well). Call the process natural selection, peer review or just mob rule, we label a cranky person “crabby” today because it seemed apt to enough people. If you’re looking for a specific person who coined the term, you might as well hang it up. It was almost certainly “invented,” over and over again, by thousands of people.

Our English word “crab” comes from the Old English “crabba,” itself from a Germanic root meaning “to scratch or claw,” which is, after all, pretty much the crab’s entire repertoire right there. Our modern “crabby,” meaning “cross, irritable, cranky” is fairly recent (as such things are measured), dating to the late 18th century. “Crabby,” however, was a derivative of an earlier term, “crabbed,” which appeared with the same meaning back in the 14th century.

In both “crabby” and “crabbed,” the analogy is to a crab’s tendency to painfully nip with its claws and tenaciously hold on, as well as its tendency to walk backwards and sideways, making it an excellent metaphor for a difficult, uncooperative person. (This, of course, is not entirely fair to crabs, many of which probably have wonderful personalities and, should they one day take over the planet, will no doubt remember I said that.) One of the more popular uses of “crabby” in this sense in recent years was in the Peanuts comic strip, in which Lucy van Pelt was routinely described as “crabby.”

The peculiar locomotion of a crab actually contributed to another sense of “crabbed,” that of “crooked, knotted, complex, twisted,” which today is found mostly in descriptions of indecipherable handwriting, awkward or overly-complex prose (“Mr. Hume, who has translated so many of the dark and crabbed passages of Butler into his own transparent and beautiful language,” 1830), or the ravages of age and disease on the human body (e.g., “a crabbed old man”).

Interestingly, the “crab,” or wild, apple, takes its name from the probably unrelated Scandinavian word “scrab” rather than the crustacean. But the sourness of the “crabapple” probably reinforced several senses of “crab” as applied to humans, especially the use of “crab” to mean “complain bitterly.”