arrest backpedal backslide backwater be found wanting brake check clip the wings cock collapse come short curb decelerate decline delay detain draw rein ease off ease up fail fall astern fall away fall behind fall short get behind go backwards go behind hold back hold in check hold up impede jerk back keep back lack lag lapse let down let up lose momentum lose speed moderate not answer not hack it not make it not make out not measure up not stretch not suffice obstruct pull back recede recidivate reef regress rein in relapse relax retard retrocede retroflex retrograde retrogress return revert run short set back slack off slack up slacken slip back slow slow down slow up slump stay stop short take in sail throttle down want