Definition of louse
(Entry 1 of 2)
1
plural lice\
ˈlīs
\
a
: any of various small wingless usually flattened insects (orders Anoplura and Mallophaga) parasitic on warm-blooded animals
b
: a small usually sluggish arthropod (such as a biting louse) that lives on other animals or on plants and sucks their blood or juices
c
: any of several small arthropods (such as a book louse) that are not parasitic
2
plural louses\
ˈlau̇-səz
\
: a contemptible person : heel
what a beast, what a cad, what a louse he had been— Walter Karig
louse
verb
loused; lousing
Definition of louse (Entry 2 of 2)
: to remove lice from
Test Your Vocabulary
Odd Habits and Quirks
-
- Which of the following best describes an easily irritated person?

Test your vocabulary with our 10-question quiz!
TAKE THE QUIZ
A daily challenge for crossword fanatics.
TAKE THE QUIZLove words? Need even more definitions?
Merriam-Webster unabridged
Share louse
Time Traveler for louse
The first known use of louse was before the 12th century
See more words from the same century