louse
UK[laʊs]US[laʊs]
n
A small, wingless insect that lives as a parasite on the bodies of humans or other animals.
n
(informal, contemptuous) A worthless or unpleasant person.
Etymology
The word "louse" descends directly from the Old English "lūs," which shares a common Proto-Germanic ancestor "lūs." This root is ancient, traceable back to Proto-Indo-European "lewH-," which carried the sense of a small, parasitic insect. The word has remained remarkably stable in both form and core meaning across millennia within the Germanic language family. Its secondary, derogatory meaning for a contemptible person is a classic example of semantic extension, drawing a metaphorical link between the parasitic nature of the insect and perceived human behavior.
Analysis
The word is a simplex. It is a Germanic root word inherited from Old English.
Examples
The school nurse checked the children's hair for head louse.
He's an absolute louse for cheating on his partner like that.
The veterinarian treated the dog for a severe louse infestation.