louse

[ noun lous; verb lous, louz ]

noun

, plural lice [lahys] lous·es

1. any small, wingless insect of the order Anoplura sucking louse, parasitic on humans and other mammals and having mouthparts adapted for sucking, as Pediculus humanus humanus body louse or Pediculus humanus capitis head louse and Phthirius pubis crab louse, or pubic louse.
2. any insect of the order Mallophaga bird louse, biting louse, or chewing louse, parasitic on birds and mammals, having mouthparts adapted for biting.
3. plant louse.
4. Slang. a contemptible person, especially an unethical one.

verb (used with object)

, loused, lous·ing.

1. to delouse.

verb phrase

1. Slang. to spoil; botch:

   Miscasting loused up the movie.

louse

/ laʊs /

noun

1. any wingless bloodsucking insect of the order Anoplura: includes Pediculus capitis ( head louse ), Pediculus corporis ( body louse ), and the crab louse, all of which infest man pedicular
2. biting louse or bird louse
   any wingless insect of the order Mallophaga, such as the chicken louse: external parasites of birds and mammals with biting mouthparts
3. any of various similar but unrelated insects, such as the plant louse and book louse
4. slang.
   louses an unpleasant or mean person

verb

1. to remove lice from
2. slang.
   foll by up to ruin or spoil

Word History and Origins

Origin of louse¹

First recorded before 900; 1910–15 louse fordef 4; Middle English lous(e), luse, plural lise, lice; Old English lūs, plural lȳs; cognate with Dutch luis, German Laus, Old Norse lūs

Word History and Origins

Origin of louse¹

Old English lūs; related to Old High German, Old Norse lūs

Example Sentences

Actress Jenny Mollen is itching to make sure everyone knows she didn’t realize she had head lice until she was already on her recent five-hour flight.

From Los Angeles Times

Wrasse fish are used to keep farmed species such as salmon free from sea lice and helps minimise the use of chemical treatments.

From BBC

There are also long-standing concerns around parasitic sea lice and the use of chemical treatments in open waters.

From BBC

Head lice, scientifically known as Pediculus humanus capitis, are tiny parasitic insects that feed on blood from the human scalp; they most frequently affect kids.

From Salon

It also appeared to have a significant amount of whale lice, which is often an indicator of poor health.

From Los Angeles Times