the GNU version of the Collaborative International Dictionary of English
adj. Destitute of expression.
The Century Dictionary and Cyclopedia
Destitute of expression.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
adj. deliberately impassive in manner
Word Usage
"It is characterized by an expressionless face, slow initiation of motor activity, loss of secondary movements (such as arm swing, which gives the patient a stiff, frozen appearance), and micrographia (handwriting becomes small and choppy)."