| around the bend |
(informal) crazy; insane. |
| barmy |
(chiefly British; informal) a bit crazy; nuts. [1/2 definitions] |
| batty |
(slang) eccentric or crazy. |
| berserk |
deranged or crazy. [1/2 definitions] |
| buggy2 |
(informal) crazy. [1/2 definitions] |
| cuckoo |
a bird of Europe and America with a slim body and a long tail. A cuckoo's color can range from gray to brown. Some cuckoos have a call that sounds like their name. [2 definitions] |
| daffy |
(informal) silly, foolish, crazy, or weak-minded in mood or temperament. |
| dotty1 |
(informal) eccentric, weak-minded, or a little crazy; daft. [1/4 definitions] |
| fruitcake |
(slang) a crazy or eccentric person. [1/2 definitions] |
| gaga |
(informal) crazy or ecstatic. |
| haywire |
(informal) acting in an unpredictable or disordered manner; crazy. [1/3 definitions] |
| insane |
having a disease of the mind; crazy; mad. [1/2 definitions] |
| kook |
(slang) a person considered to be strange or crazy. |
| loco |
(slang) crazy; mad; insane. [1/3 definitions] |
| loony |
insane; crazy; lunatic. [1/3 definitions] |
| mad |
crazy; insane. [1/6 definitions] |
| mad as a hatter |
wildly impulsive or completely crazy. |
| mental |
(informal) crazy; insane. [1/4 definitions] |
| meshuga |
(informal) crazy; insane. |
| nut |
(slang) a foolish or crazy person. [1/4 definitions] |
| nut case |
(slang) one who is unbalanced or crazy. |