Lice are the small wingless insects that live on skin and hair. Head lice, check for lice, treat the lice.
The singular is louse. Head lice are extremely common in primary schools and have nothing to do with cleanliness — they prefer clean hair. Detection combing on wet conditioned hair is the reliable check, and treatment is either a chemical or repeated combing. Body lice are different and do spread disease. Note nit, which is the egg rather than the insect; and nitpicking, which comes from removing them one at a time.
1nounliceSmall wingless insects that live on skin and hair.
“Lice spread quickly when children put their heads together.”
lice is small parasitic insects.
Old English lys is the plural of lus, and the vowel change is the same one that gives mouse and mice, goose and geese. It is one of about seven such plurals left in English.
Old English
lȳs
Middle English
lys
English, today
lice
From Middle English lys, from Old English lȳs.
Etymology from Wiktionary, CC BY-SA