The Collaborative International Dictionary of English v.0.48:

Temporizer \Tem"po*ri`zer\, n.
   One who temporizes; one who yields to the time, or complies
   with the prevailing opinions, fashions, or occasions; a
   trimmer.
   [1913 Webster]

         A sort of temporizers, ready to embrace and maintain
         all that is, or shall be, proposed, in hope of
         preferment.                              --Burton.
   [1913 Webster]

WordNet (r) 3.0 (2006):

temporizer
    n 1: someone who temporizes; someone who tries to gain time or
         who waits for a favorable time [syn: temporizer,
         temporiser]