Puzzle of the Week #35 - Odd Word Out

What is the odd word in this list and why?

SEEK
BUY
TEACH
FIGHT

Notoriously, with odd-one-out questions, you will probably be able to find a reason why each of the words in turn should be the odd one. However, the true solution will be both convincing and satisfying, with even my choice of the odd word serving to support your hypothesis. Good luck!