crab

Etymology 1

From Middle English crabbe, from Old English crabba (“crab; crayfish; cancer”), from Proto-West Germanic *krabbō, from Proto-Germanic *krabbô, from *krabbōną (“to creep, crawl”), from root *kraƀ (“scrape”), from Proto-Indo-European *grobʰ- (“scratch, claw at”), a variant of *gerbʰ-. More at carve. Cognates See also Dutch krab, Low German Krabb, Danish krabbe, Swedish krabba, Dutch krabben. Further cognates with frequentative-infix are Saterland Frisian krabbelje (“to creep, crawl”), Dutch krabbelen (“to scratch”) and German krabbeln (“to crawl”).

noun

1. A crustacean of the infraorder Brachyura, having five pairs of legs, the foremost of which are in the form of claws, and a carapace.
2. (uncountable) The meat of this crustacean, served as food; crabmeat.
   But Richmond[…]appeared to lose himself in his own reflections. Some pickled crab, which he had not touched, had been removed with a damson pie; and his sister saw[…]that he had eaten no more than a spoonful of that either. 1959, Georgette Heyer, chapter 1, in The Unknown Ajax
3. A bad-tempered person.
4. (in plural crabs, informal) An infestation of pubic lice (Pthirus pubis).
   Although crabs themselves are an easily treated inconvenience, the patient and his partner(s) clearly run major STD risks.
5. (uncountable, aviation) The angle by which an aircraft's nose is pointed upwind of its groundtrack to compensate for crosswinds during an approach to landing; its crab angle.
   The pilot had to hold fifteen degrees of crab during the approach to keep her plane from getting blown off the localizer course.
6. (uncountable, aviation) The state of an aircraft's nose being pointed upwind of its groundtrack to compensate for crosswinds during an approach to landing.
7. (slang) A playing card with the rank of three.
8. (rowing) A position in rowing where the oar is pushed under the rigger by the force of the water.
9. A defect in an outwardly normal object that may render it inconvenient and troublesome to use.
   -- "I suppose you wouldn't like to do a locum for a month on the South coast? Three guineas a week with board and lodging." -- "I wouldn't mind," said Philip. -- "It's at Farnley, in Dorsetshire. Doctor South. You'd have to go down at once; his assistant has developed mumps. I believe it's a very pleasant place." There was something in the secretary's manner that puzzled Philip. It was a little doubtful. -- "What's the crab in it?" he asked. 1915, W.S. Maugham, “chapter 116”, in Of Human Bondage
   Arrested by the low price of another “desirable residence”, I asked “What's the crab?” The agent assured me that there was no crab. I fell in love with this house at sight. Happily, I discovered that it was reputed to be haunted. 1940, Horace Annesley Vachell, Little Tyrannies
10. (dated) An unsold book that is returned to the publisher.
    […] the unsold copies may be returned to the original publisher , at a period fixed upon between Christmas and Easter; these returned copies are technically called krebse or crabs, probably, from their walking backwards. […] A says to B, "I have had eight thousand dollars' worth of your publications, three thousand were crabs, that makes five thousand." 1844, Albert Henry Payne, Payne's universum, or pictorial world, page 99
    […] unsold copies and settling the yearly accounts; while for the publisher begins the much dreaded season of "crabs," as […] 1892, The Publishers Weekly, volume 41, page 709

verb

1. (intransitive) To fish for crabs.
2. (transitive, US, slang) To ruin.
   I thought at the time that that little speech meant a savin' of eight dollars,[…] But the Missus crabbed it a few minutes after her and Bess come in the room. 1916, Ring W. Lardner, “Three Kings and a Pair”, in The Saturday Evening Post
   ‘Just so we understand each other,’ he said after a pause. ‘If you crab this case, you'll be in a jam.’ 1940, Raymond Chandler, Farewell, My Lovely, Penguin, published 2010, page 224
3. (intransitive) To complain.
   And if we do have to walk, I don't want to have to listen to you crabbing at me, Tad Trenton. 1981, Stephen King, Cujo, published 2001, page 163
4. (transitive) To complain about.
   Well, because of this state of things they crabbed his scheme from the first, ridiculed it, wrote against it, spread broadcast a feeling of distrust. 2007, Douglas Newton, Dr. Odin, page 24
5. (intransitive) To drift or move sideways or to leeward (by analogy with the movement of a crab).
   Mutt stalked forward, matching him, step for step, crabbing sideways the way wolves do when they're going for the kill. 2000, Dana Stabenow, Midnight Come Again, page 251
   The aircraft crabbed sideways in the cross-winds and leveled to horizontal. 2007, Pat DePaolo, The Beijing Games, page 454
   Another shouted order and again the squares crabbed sideways. 2015, Andrew Swanston, Waterloo: The Bravest Man
6. To move in a manner that involves keeping low and clinging to surfaces.
   Time slowed down then, became liquid in the aftermath of his grotesque, unfolding limbs; he crabbed his way down the faded line, rocking back and forth in braces he would use all his life. 2011, Robert Vivian, The Least Cricket of Evening, page 108
   Foot by foot, he crabbed his way down another ninety feet of rock chimney until he stood on solid ground again, still very much alive. 2019, Ronan Frost, White Peak
7. (transitive, aviation) To navigate (an aircraft, e.g. a glider) sideways against an air current in order to maintain a straight-line course.
8. (transitive, film, television) To move (a camera) sideways.
   If panning is not easy to make seem natural, crabbing the camera is even less like any action we perform with our eyes in the real world. There are a few circumstances in which we walk sideways: […] 1997, Paul Kriwaczek, Documentary for the Small Screen, page 109
9. (obsolete, World War I), to fly slightly off the straight-line course towards an enemy aircraft, as the machine guns on early aircraft did not allow firing through the propeller disk.
10. (rare) To back out of something.

Etymology 2

From Middle English crabbe (“wild apple”), of Germanic origin, plausibly from North Germanic, cognate with Swedish dialect scrabba.

noun

1. The crab apple or wild apple.
2. The tree bearing crab apples, which has a dogbane-like bitter bark with medical use.
3. A cudgel made of the wood of the crab tree; a crabstick.
   She swore to such things , that I could do nothing but swear and call names : upon which out bolts her husband upon me , with a fine taper crab in his hand and fell upon me with such violence , that , being half delirious , I made a full confession 1741, David Garrick, The Lying Valet
4. A movable winch or windlass with powerful gearing, used with derricks, etc.
5. A form of windlass, or geared capstan, for hauling ships into dock, etc.
6. A machine used in ropewalks to stretch the yarn.
7. A claw for anchoring a portable machine.

verb

1. (obsolete) To irritate, make surly or sour
2. To be ill-tempered; to complain or find fault.
3. (British dialect) To cudgel or beat, as with a crabstick
   Get you to bed, drab, courage Or l'll so crab your shoulders! 1639, John Fletcher, Monsieur Thomas
   I was on a horse named The Skipper, a perfect terror to ride when he was in a bad humour, which he invariably was; nevertheless he was a splendid hunter and I never crabbed him. 1935, Jack Molyneux, John Fairfax-Blakeborough, Thirty Years a Hunt Servant: Being the Memories of Jack Molyneux, page 161
   The Shiremans had a down on him over stores he'd condemned as not fit for dogs, let alone able seamen, and they'd got wind he was a socialist, and they crabbed him all over the shipping companies' offices. 2021, H. De Vere Stacpoole, Vanderdecken

Etymology 3

Possibly a corruption of the genus name Carapa

noun

1. The tree species Carapa guianensis, native to South America.

Etymology 4

From carabiner.

noun

1. (informal) Short for carabiner.