What is fence? What is fence? A structure serving as an enclosure, a barrier, or a boundary, usually made of posts or stakes joined together by boards, wire, or rails.The art or sport of fencing.One who receives and sells stolen goods. A place where stolen goods are received and sold.Archaic A means of defense; a protection.To enclose with or as if with a fence. See Synonyms at enclose.To separate or close off by or as if by means of a fence.To ward off; keep away.To defend.To sell (stolen goods) to a fence.To practice the art or sport of fencing.To use tactics similar to the parry and thrust of fencing.To avoid giving direct answers; hedge.To act as a conduit for stolen goods.on the fence Informal Undecided as to which of two sides to support; uncommitted or neutral.