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 small, wingless, parasitic insect of the order Siphonaptera, renowned for its bloodsucking habits and jumping abilities.
A thing of no significance.
To remove fleas from (an animal).