It's an abbreviation of the word feelings, probably because it's easier to type a five letter word or to keysmash.

Matt Damon, playing an assassin without a cause, gets to show off some very deftly timed martial-arts moves, flipping his limbs around with the slashy percussive precision of ninja nunchakus.

Would his unconscious feelings of inadequacy be overcome by his Herostratic act (considered as expiation through punishment)?

I scribbled the measurements on the wall with a koki.