fluke

Etymology 1

Of uncertain or obscure origin, perhaps dialectal. It seems to have originally referred to a lucky shot at billiards. Possibly connected to sense 3, referring to whales' use of flukes to move rapidly.

noun

1. A lucky or improbable occurrence, with the implication that the occurrence could not be repeated.
   The first goal was just a fluke.
   "And I say," said Wimsey, "that it would be better for her to be hanged outright than to live and have everybody think her a murderess who got off by a fluke." 1930, Dorothy L. Sayers, Strong Poison
   It's Christmas at ground zero / Now the missiles are on their way / What a crazy fluke / We're gonna get nuked / On this jolly holiday 1986, "Weird Al" Yankovic (lyrics and music), “Christmas at Ground Zero”, in Polka Party!
   And before I forget... that was one amazing kiss, mister. Could have been a fluke, though. Guess we have to keep trying. 2017, BioWare, Mass Effect: Andromeda (Science Fiction), Redwood City: Electronic Arts, →OCLC, PC, scene: Garden
   That this was not just a fluke was proved by a further profit the following year, albeit cut due to industrial action - jam at last! January 2 2020, David Clough, “How InterCity came back from the brink”, in Rail, page 69

verb

1. To obtain a successful outcome by pure chance.
   I fluked a pass in the multiple-choice exam.
2. (snooker) To fortuitously pot a ball in an unintended way.
   He fluked the other red into the middle pocket, despite the double kiss.

Etymology 2

From Old English flōc (“flatfish”), of Germanic origin, related to German flach (“flat”), Old Norse floke (“flatfish”), all ultimately from Proto-Germanic *flakaz.

noun

1. The summer flounder (Paralichthys dentatus)
2. A trematode; a parasitic flatworm of the Trematoda class, related to the tapeworm.
   The man became infected with flukes after eating a meal of raw fish.

Etymology 3

Possibly as Etymology 2 or from Middle Low German flügel (“wing”), from Old High German vlügel, from Proto-Germanic *flugilaz (“wing”).

noun

1. Either of the two lobes of a whale's or similar creature's tail.
   The dolphin had an open wound on the left fluke of its tail where the propeller had injured it.
2. (nautical) Any of the triangular blades at the end of an anchor, designed to catch the ground.
   The fluke of the anchor was wedged between two outcroppings of rock and could not be dislodged.
3. A metal hook on the head of certain staff weapons (such as a bill), made in various forms depending on function, whether used for grappling or to penetrate armour when swung at an opponent.
   The polearm had a wide, sharpened fluke attached to the central point.
4. In general, a winglike formation on a central piece.
   After casting the bronze statue, we filed down the flukes and spurs from the molding process.
5. Waste cotton.