drop dead

Short definition from Wiktionary

Verb

1. 1
   To die suddenly.
2. 2
   To be appalled or mortified.

Interjection

1. 1
   Used angrily to express disgust, contempt, derision, etc., toward another person.

Adverb

1. 1
   Alternative form of drop-dead.
2. 2
   Very impressively or spectacularly.
3. 3
   Absolutely final; being the deadline, especially in relation to a date set out in a contract upon which adverse consequences will flow if the contract has not been fulfilled.