Merriam-Webster's Collegiate® Dictionary, 11th Edition
PREFIX
I. transitive verb
Etymology: Middle English, from Middle French prefixer, from Latin praefixus
Date: 15th century
to fix or appoint beforehand, to place in front,
II. noun see: fix
Date: 1646
an affix attached to the beginning of a word, base, or phrase and serving to produce a derivative word or an inflectional form, a title used before a person's name, prefixal adjective
III. adjective
Date: 1971
characterized by placement of an operator before its operand or before its two operands if it is a binary operator