n.
The pigment sensitive to red light in the retinal rods of the eyes, consisting of opsin and retinene. Also called visual purple.
[RHOD(O)- + Greek opsis, sight; see -opsis + -IN.]
The American Heritage® Dictionary of the English Language, Fourth Edition Copyright © 2007, 2000 by Houghton Mifflin Company. Updated in 2009. Published by Houghton Mifflin Company. All rights reserved.
