[*** \mathrm{fluke}^1] |flo͞ok|

an unlikely chance occurrence, especially a surprising piece of luck:

｟くだけて｠ 〖通例単数形で〗まぐれ当たり, 幸運(な出来事), フロック

e.g. their triumph was no fluke.

mid 19th century (originally a term in games such as billiards denoting a lucky stroke): perhaps a dialect word.

[*** \mathrm{fluke}^2] |flo͞ok|

1. a parasitic flatworm which typically has suckers and hooks for attachment to the host. Some species are of veterinary or medical importance.

〘虫〙 吸虫(類)

2. dialect or North American a flatfish, especially a flounder.

〘魚〙 平たい魚の総称

Old English flōc (in fluke2 (sense 2)), of Germanic origin; related to German flach ‘flat’.

[*** \mathrm{fluke}^3] |flo͞ok|

a broad triangular plate on the arm of an anchor.

錨づめ［かぎ］.

either of the lobes of a whale's tail.

クジラの尾の先端

mid 16th century: perhaps from fluke2 (because of the shape).