prefix

(grammar, linguistic morphology) A morpheme added to the beginning of a word to modify its meaning, for example as, pre- in prefix, con- in conjure, re- in reheat, etc.

(telecommunications) A set of digits placed before a telephone number, to indicate where the number is based, what type of phone number it is (landline, mobile, toll-free, premium rate etc.)

A title added to a person's name, such as Mr. or Dr.

(computing) An initial segment of a string of characters.