Choose the correct one-word substitute for: 'A secret or disguised way of writing'.

Correct — A. A cipher is a secret or disguised way of writing: a system that swaps or scrambles letters so that only someone holding the key can read the message.

The trigger in the definition is secret, and nothing in the other three words is hidden → option (a).

Why the others are wrong

• (b)
  Epistle — Epistle is a letter, especially a long or formal one, like the epistles of the New Testament. Nothing about it is secret or disguised.
• (c)
  Diatribe — Diatribe is a bitter, forceful attack in speech or writing. It is about tone, not secrecy: a diatribe wants to be understood.
• (d)
  Manuscript — Manuscript is a text written by hand, or an author's draft before printing. It describes how a text was produced, not whether it is hidden.

Cipher, also spelt cypher, has three senses worth knowing. The one tested here is a secret or disguised way of writing, a code.

It also means zero, the figure 0, and from that a person of no importance, as in 'a mere cipher'. The word comes through medieval Latin from Arabic ṣifr, 'zero'.

To decipher is to turn a cipher back into plain text, and by extension to make out anything hard to read.

Key facts

• Cipher, also spelt cypher, is a secret or disguised way of writing.
• Cipher also means zero, and a person of no importance.
• The word comes through medieval Latin from Arabic ṣifr, 'zero'.
• Decipher means to turn coded text into plain language, or to make out hard-to-read writing.

Common traps

• Taking manuscript as secret writing because old manuscripts can be hard to read
• Knowing cipher only as zero and ruling it out

No directly related past PYQ was found.