1. a small wingless insect that lives as a parasite on humans and other mammals
2. a contemptible or unpleasant person
Usage: informal

1. to remove lice from
2. to spoil or bungle something
Usage: informal

Examples

• The child had head lice and needed special shampoo treatment.
• Body lice were a serious problem for soldiers in the trenches.
• Don’t be such a louse – help your sister with her homework.
• The mother carefully loused her daughter’s hair with a fine comb.
• He really loused up the presentation with his poor preparation.
• The veterinarian showed us how to louse our dog properly.