from The American Heritage® Dictionary of the English Language, 4th Edition
- n. Contraction of the pupil of the eye in response to an increase in light.
from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
- n. reflex contraction of the sphincter muscle of the iris in response to a bright light (or certain drugs) causing the pupil to become smaller
Sorry, no etymologies found.