suprisingly, the 'k' is pronounced. knublets are nubs that sway back and forth when they get nervous or excited. in tense moments, knublets can be observed swaying at high enough speeds to generate a distinct humming sound.
at a lan party:
player1: do you hear that sound?
player2: yeah, it's a knublet, you fuckin nub. ignore it and zerg rush, k?