Dictionary.com
definitions

train wreck

or train·wreck

[trein-rek]
noun
  1. an accident in which a train or trains are severely damaged.
  2. Slang. a person who has experienced a personal failure, disaster, etc.
  3. Slang. a disastrous situation, occurrence, or process: His football career has been a train wreck.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
British Dictionary definitions for train wreck

train wreck

noun
  1. an incident in which a train is severely damaged
  2. informal something or someone that has suffered ruin or calamity
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012