The Collaborative International Dictionary of English v.0.48:

emotionless \e*mo"tion*less\ adj.
   1. unsusceptible to, destitute of, or showing no emotion;
      unmoved by feeling. Opposite of emotional; as, he kept
      his emotionless objectivity and faith in the cause he
      served. [Narrower terms: matter-of-fact, prosaic;
      philosophical, philosophic; phlegmatic, phlegmatical,
      stolid; stoic, stoical; unblinking] Also See: cool,
      passionless, unmoved(predicate), unmoving.

   Syn: unemotional, passionless.
        [WordNet 1.5]

WordNet (r) 3.0 (2006):

unblinking
    adj 1: showing no visible emotion; "stood unblinking and
           accepted a sentence of a year"
    2: not shrinking from danger [syn: unblinking, unflinching,
       unintimidated, unshrinking]