expressionless
UK: ɪkˈsprɛʃənləs | US: ɪkˈsprɛʃənləs
adj. lacking emotional or facial expression; showing no feeling or animation.
The word "expressionless" combines "expression," derived from Latin expressio (from exprimere, meaning "to press out" or "to represent"), with the suffix "-less," an Old English morpheme meaning "without." The fusion creates a vivid image of a face or manner that "presses out" no emotion or thought. Over time, "expression" evolved to specifically denote facial or verbal communication, while "-less" universally negates the root's meaning.
Her expressionless stare made it impossible to guess her thoughts.
The actor delivered his lines in a flat, expressionless tone.
Despite the shocking news, he remained expressionless.
The portrait was criticized for its expressionless depiction of the subject.
He nodded expressionlessly, giving no clue to his agreement or disagreement.