1. (v. t.) To keep delaying; to continue to hinder; to prevent from progress; to render more slow in progress; to impede; to hinder; as, to retard the march of an army; to retard the motion of a ship; -- opposed to accelerate.

2. (v. t.) To put off; to postpone; as, to retard the attacks of old age; to retard a rupture between nations.

3. (v. i.) To stay back.

4. (n.) Retardation; delay.

arrest backpedal backwater balk block bottle up brake bridle check clip the wings confine constrain contain control cool cool off countercheck curb curtail dam up damp dampen decelerate delay detain dompt drag draw rein dunce ease off ease up enjoin fool frustrate govern guard hinder hold hold at bay hold back hold fast hold in hold in check hold in leash hold up idiot imbecile impede inhibit intercept interfere interfere with intermeddle interrupt intervene jerk keep keep back keep from keep in keep in check keep under control lag lay under restraint let down let up lose ground lose momentum lose speed make late meddle moderate moron obstruct oppose prohibit pull pull in reef rein rein in relax repress resist restrain restrict retrench scotch set back slack off slack up slacken slow slow down slow up snub stall stay stop straiten suppress take in sail throttle down thwart withhold