The prefix for the word 'BEFORE' is 'pre'. Pre is a Latin prefix meaning 'BEFORE'. It is used to form words that indicate something happening BEFORE a certain point in time or BEFORE a certain event. For example, 'pre-election' refers to events that occur BEFORE an election, and 'pre-war' refers to events that occur BEFORE a war. Pre is also used to form words that indicate something occurring in advance of a certain point in time or event, such as 'pre-order' or 'pre-payment'.