prefix

/ˈpriːfɪks/
noun
  1. A letter or group of letters added to the beginning of a word to change its meaning, such as 'un-' in 'unhappy'.
    • Adding the prefix 'dis-' to 'agree' creates the word 'disagree'.
    • The prefix 're-' means 'again', as in 'rewrite'.
    • Many English words are formed by adding a prefix to a base word.
  2. A title or word placed before a person's name, such as 'Dr.' or 'Mr.'.
    • On the envelope, she wrote the prefix 'Ms.' before her last name.
    • Please include your name and prefix on the registration form.
    • The prefix 'Sir' is used for knights in the United Kingdom.
  3. A code or number placed at the beginning of a telephone number, indicating a region or service.
    • To call London, you need to dial the country prefix '44' first.
    • The area code is a three-digit prefix for your phone number.
    • My phone number has the prefix 555.
Antonyms
verb
  1. To add a letter, group of letters, or word at the beginning of something.
    • You should prefix the file name with the date.
    • In English, we often prefix 'un-' to adjectives to make them negative.
    • The teacher asked us to prefix our answers with the question number.
What does "prefix" mean? | whatsthatwordmean | whatsthatwordmean