资料来源 : Webster's Revised Unabridged Dictionary (1913)

Withholder \With*hold"er\, n.
   One who withholds.

资料来源 : WordNet®

withholder
     n 1: a person who refrains from granting; "a withholder of
          payments" [ant: {granter}]
     2: a person who restrains or checks or holds back