the Mad Hatter

Từ điển Oxford Advanced Learner 8th

the Mad Hatter [the Mad Hatter] BrE NAmE
a character in ↑Alice in Wonderland by Lewis Carroll. The Mad Hatter, who wears a tall hat, holds a ↑tea party with Alice, the March Hare and the Dormouse. The expression ‘as mad as a hatter’, meaning completely crazy, was already common when Carroll wrote the book.