swordfish

Short definition from Wiktionary

Noun

1. 1
   A large marine fish with a long, pointed bill, Xiphias gladius.
2. 2
   A sudoku technique involving possible cell locations for a digit, or pair, or triple, in uniquely three rows and three columns only. This allows for the elimination of candidates around the grid.

Verb

1. 1
   To fish for swordfish.