- the action of a gene in the production of a protein or a phenotype.
- expressivity(def 2).
Origin of expression
Examples from the Web for expressionless
At the time Milke entered death row, she was 26 years old, tall and slender with expressionless blue eyes and permed brown hair.
In photographs, he says, she sports one of those “blank, expressionless faces” that lack variety and emotion.
Little Hossein was pale and his eyes looked glassy and expressionless.
Through all the wild whirl, straight and erect and commanding was the form of Bob, his face cold and expressionless as an iceberg.Friday, the Thirteenth|Thomas W. Lawson
Her smile fled and her features altered to an expressionless and colourless mask.The Business of Life|Robert W. Chambers
The escaped convict was a middle-aged, sullen looking man with hard, expressionless eyes.Swamp Island|Mildred A. Wirt
They closed once or twice, opened again, blue-green, expressionless.The Firing Line|Robert W. Chambers
They seemed dull and expressionless, like the eyes of a new baby, but he was back for the world again.Joe Wilson and His Mates|Henry Lawson