A FLUKE is the part of an anchor or harpoon or spear or arrow that is BARBED
A FLUKE is a flounder or other flat fish
A FLUKE is either half of the triangular tail of a whale
A FLUKE is an accidental advantage. A stroke of good luck.
It was a fluke that the Fluke escaped the fluke of the harpoon and twitch of the whale fluke.