To go too far with
something; to do something crazy.
Example:
1) My mom
has always collected dolls, but I'm afraid she's gone off the deep end --
she buys 10 dolls a day on eBay!
Etymology:
The deep water, which is at the 'deep end'
of a pool, is dangerous. You can get lost in the deep end. This phrase
refers to that danger, but in an emotional rather than physical sense.
Synonyms:
lose
one's mind
Definition:
To be extremely angry.
Example:
1) When the bank told me that they lost my paycheck, I went off the deep end.
