Word.ws English Dictionary

cilly

cilly noun: any predictable facet of the Enigma Machine cipher due to operator error or laziness.

Noun

cilly (plural cillies)

  1. (historical) Any predictable facet of the Enigma Machine cipher due to operator error or laziness.
    • Another type of cilly was the repeated use of the same message key, perhaps the initials of the operator's girlfriend […]2000, Simon Singh, The Code Book
    • Answer c is a reference to a cilly, which was a three-character message key used in the German Enigma machine.2002, Ronald L Krutz, Russell Dean Vines, The CISSP Prep Guide: Gold Edition

Forms of cilly

pluralcillies

Origin of cilly

Uncertain; possibly a pun on silly and the letters CIL used as a cryptographic key.

Questions about cilly

What does cilly mean?
Cilly means any predictable facet of the Enigma Machine cipher due to operator error or laziness.
What part of speech is cilly?
Cilly is a noun.
What is the plural of cilly?
The plural of cilly is cillies.

Words near cilly in the dictionary

  1. Cilleys
  2. cillies
  3. Cillo
  4. Cillos
  5. cills
  6. cilly
  7. cilnidipine
  8. cilobamine
  9. cilobradine
  10. cilofungin
  11. cilomilast

Source and license

Adapted from Wiktionary: cilly (page history and authors). Text available under the Creative Commons Attribution-ShareAlike 4.0 license. Word.ws reformatted the entry and added links. Wiktionary data of 2026-09-02.

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