Source : WordNet®

hold back
     v 1: hold back, as of a danger or an enemy; check the expansion
          or influence of; "Arrest the downward trend"; "Check the
          growth of communism in Sout East Asia"; "Contain the
          rebel movement"; "Turn back the tide of communism" [syn:
           {check}, {turn back}, {arrest}, {stop}, {contain}]
     2: keep under control; keep in check; "suppress a smile"; "Keep
        your temper"; "keep your cool" [syn: {restrain}, {suppress},
         {keep}, {keep back}]
     3: wait before acting [syn: {wait}, {hold off}]
     4: secure and keep for possible future use or application; "The
        landlord retained the security deposit"; "I reserve the
        right to disagree" [syn: {retain}, {hold}, {keep back}]
     5: hold back; keep from being perceived by others; "She
        conceals her anger well" [syn: {conceal}, {hold in}]