1.HBBa large NorthAmericanbird that eats fish and that makes a long high sound 〔北美〕潜鸟
2.STRANGE informal a silly or strange person – used humorously 傻子;怪人〔幽默用法〕
Examples from the Corpus
loon• Rosie, the woman is crazy as a loon.• Would you laugh like a loon at such stupid things?• Why add them, with their evocation of the doddering loon, slumped, with listless ear-trumpet, over the board table?• All the eye can see are evergreens, a placid body of water and the occasionalloon.• The princess in the tower, the loon in the attic!
Originloon
1. (1600-1700) From a Scandinavian language.
2. (1600-1700)loun“bad person”((15-19 centuries)) (influenced by → LOON1 (because of its wild sound) and by → LOONY1)