Count on the English language's Latin lexical options to pretty up the unpleasant. You can have an entire conversation about lice and avoid the l-word entirely using "pediculous" and its relatives. None of the words (from pediculus, meaning "louse") is remotely common - most of them are so uncommon that they appear only in our Unabridged dictionary - but they're all available to you should you feel the need for them. There's pediculosis, meaning "infestation with lice;" pedicular, meaning "of or relating to lice;" and pediculoid, meaning "resembling or related to the common lice." "Pediculid" names a particular kind of louse - one of the family Pediculidae. And if you'd like to put an end to all of this you might require a "pediculicide" - defined as "an agent for destroying lice."