|—n , pl lice, louses|
|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 manRelated: pedicular|
|2.||biting louse, 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 an unpleasant or mean person|
|5.||to remove lice from|
|[Old English lūs; related to Old High German, Old Norse lūs]|
n. pl. lice (līs)
Any of numerous small, flat-bodied, wingless biting or sucking insects of the orders Mallophaga or Anoplura, many of which are external parasites on humans.
louse (sth) up definition
Spoil, ruin, bungle. For example, The bad weather loused up our plans, or Your change of mind really loused me up. This slangy expression originated in World War I, when infestation with lice was the common lot of soldiers in the trenches; its figurative use dates from the 1930s.