encipher

The verb 'encipher' is a relatively modern formation, entering English in the late 16th century. It was constructed by combining the intensive or causative prefix 'en-', derived from Latin 'in-', with the noun 'cipher'. 'Cipher' itself has a fascinating journey, originating from the Arabic 'ṣifr', meaning "zero" or "empty," which entered Medieval Latin as 'cifra' and Old French as 'cifre'. The semantic link from "zero" to "secret code" developed because early codes often used numbers, and the concept of zero was a novel, almost mystical, mathematical idea. Thus, 'encipher' literally means "to put into code," logically describing the action of transforming plain text into a secret numerical or symbolic cipher.

Structure: en (cause to be) + cipher (code) - en: A prefix of Latin origin (via French), meaning "to cause to be," "put into," or "cover with." - cipher: A word of Arabic origin (via Medieval Latin and French), meaning "code" or "zero," here used in the sense of a secret writing system.