emergency in WordNet English dictionary

1. a brake operated by hand; usually operates by mechanical linkage
   hand brake  emergency  emergency brake  parking brake 
   
2. a sudden unforeseen crisis (usually involving danger) that requires immediate action
   "he never knew what to do in an emergency"
   emergency  exigency  pinch 
   
3. a state in which martial law applies
   "the governor declared a state of emergency"
   emergency