Proper noun

1. a small portable electro-mechanical rotor machine used to encrypt and decrypt secret messages, made famous by Germany in WWII
2. fig. something which decrypts or makes understandable something enigmatic (see quotation)

Quotations

• 2004: No one needed an Enigma machine to figure out why Jimmy Carter was recalling his days aboard a nuclear submarine — New Yorker, 9 - 16 August 2004, p.37