Merriam-Webster Collegiate Dictionary - prefix

 I. transitive verb  Etymology: Middle English, from Middle French ~er, from Latin praefixus  Date: 15th century  1. to fix or appoint beforehand  2. partly from ~ (II) to place in front; especially to add as a ~ ~ a syllable to a word  II. noun  Etymology: New Latin praefixum, from Latin, neuter of praefixus, past participle of praefigere to fasten before, from prae- + figere to fasten — more at fix  Date: 1646  1. an affix attached to the beginning of a word, base, or phrase and serving to produce a derivative word or an inflectional form — compare suffix  2. a title used before a person's name  • ~al 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 — compare infix, postfix