be as mad as a hatter

to be crazy

Usage notes: A long time ago, people who made hats used a substance that gave them an illness which made people think they were crazy.

Her brother's as mad as a hatter.

Name	Pronounced	Usage
LÍLe	-	Irish
Mcneal	[mək'ni:l]
Elvira	el-BEE-rah (Spanish), el-VEE-rah (Italian)	Spanish, Italian, Portuguese, German, Dutch, Russian
Kunti	-	Hinduism
ClÍOdhna	KLEE-u-na	Irish, Irish Mythology
Rani (2)	-	Hebrew