From BiblePortal Wikipedia

Webster's Dictionary [1]

(n.) One who conquers.

International Standard Bible Encyclopedia [2]

kon´kẽr - ẽr  : Known only in the compound verb (ὑπερνικῶμεν , hupernikō̇men ,  Romans 8:37 ): A usual meaning of the preposition in composition is "above all measure"; hence, "more than conquerors," the Revised Version (British and American), the King James Version. The comparison is to the completeness of the victory. Others may place their enemies in subjection; those here mentioned master not only their foes, but themselves. Others destroy their foes and their resources; while those who are "more than conquerors" convert foes into means of still farther promoting the interests for which they struggle ( Romans 3:3-5 ). Nor is the victory external and transient, but internal and permanent.