(flk) noun
1. Naut. The part of an anchor that holds to the ground.
2. One of the lobes of the tail of a whale.
3. A barb on a harpoon, arrow, etc. [? <FLUKE²]
FLUKE¹ (def. 3)

(flk) noun
1. A leaflike, parasitic, trematode worm infesting sheep, and also man and other animals: also called fluke worm.
2. A flatfish or flounder. [OE flōc]

(flk) noun
1. A lucky stroke or accident, as in billiards, etc.
2. Colloq. An accidental failure or disappointment, as from a capricious wind in sailing. [Origin unknown]