A louse (Pediculus humanus).
Any germ or contaminant, real or imagined, especially from the opposite gender (for pre-pubescent children).
A sideswiper, a type of telegraph key.
A nest-building female American coot (counterpart to cooter).
A large wasp, of the genus Vespa, having a brown-and-yellow-striped body and the ability to inflict a serious sting.
A person who pesters with petty but ceaseless attacks.