1) A cocky bacteria.

2) A form of describing an arrogant person by equating them with the cheese-like bacteria that accumulates beneath the foreskin of an unclean/unhygienic person.
Person A: What is up with that guy? He won't even stop talking on his bluetooth headset while the server takes his order!

Person B: Smugma.
by mercury895 November 16, 2010
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Something reeeeaaally disgusting.
Eew, look at the smugma in that trash can!
by Aaron W. December 6, 2002
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