RETARD

I. verb Etymology: Middle English, from Anglo-French or Latin; Anglo-French ~er, from Latin ~are, from re- + tardus slow Date: 15th century transitive verb to slow up especially by preventing or hindering advance or accomplishment ; impede , to delay academic progress by failure to promote, intransitive verb to undergo ~ation, see: delay ~er noun II. noun Date: 1788 a holding back or slowing down ; ~ation , a ~ed person