An accretion of miscellaneous fabric that gathers in the recess of a navel. Can be speroidal in shape cemented by sweat and other bodily secretions making retreival only possible with a long fingernail or tweezers.

the thing that you don’t have when you’re phones percentage is over 20

belly-button lint is an accumulation of fabric particles that collects in a guy's navel and smells like cum.