pre

Pre is a productive prefix in English and many languages, derived from the Latin prae- meaning "before" or "in front of." It attaches to a wide range of roots to express anteriority in time, order, or priority, and it often indicates that something occurs earlier than another reference point. It contrasts with post- meaning after and with pro- meaning forward or in favor.

Usage spans verbs, adjectives, nouns, and adverbs. With verbs it denotes preparation or anticipation (prepare, preheat, prearrange). With adjectives it marks earlier form or timing (prehistoric, prenatal, preterm, prewar). With nouns it can indicate an earlier version or preliminary stage (preliminary, preface).

In computing, the HTML pre element designates preformatted text: spaces and line breaks are preserved, and a fixed-width font is typically used. This makes it suitable for displaying computer code or other preformatted content. The effect can also be achieved in CSS with the white-space: pre setting.

In medicine and anatomy, pre- is used to describe positions or events before a reference point: preoperative means before surgery; prenatal before birth; prefrontal refers to the region in front of the frontal lobe. Preterm denotes birth before the usual term. The prefix is also used in many other technical terms to indicate prior occurrence or status.