forty weepy weepy

Etymology
From a message whose plaintext began fortyweepyyweepy:, short for + weep, typewriter code for 23:30, the time of the previous message. Enigma machines had no number keys, so the letter y marked the letters to be interpreted as numbers.

Noun

 * 1)  Cryptanalysis of an Enigma message which was a continuation of a previous message sent at a known time.