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).
Any of various insects of the order Hemiptera and in particular of the suborder Heteroptera, that are wingless or have two pairs of wings, and have mouthparts adapted for piercing and sucking.