Why was clemency trending last week?


[ret-n-uh l] /ˈrɛt n əl/
of or relating to the retina of the eye.
Origin of retinal1
1830-40; retin(a) + -al1


[ret-n-al, -awl] /ˈrɛt nˌæl, -ˌɔl/
noun, Biochemistry
an orange pigment, C 2 0 H 2 8 O, that is the active component of rhodopsin and is liberated upon the absorption of light in the vision cycle; vitamin A aldehyde.
Also, retinene
[ret-n-een] /ˈrɛt nˌin/ (Show IPA)
1940-45; retin(a) + -al3 Unabridged
Based on the Random House Dictionary, © Random House, Inc. 2015.
Cite This Source
Examples from the web for retinal
  • In vertebrates this protein is found in retinal cells, where it transduces the energy of light into a nerve signal to the brain.
  • Claims the market for a successful retinal prosthesis is significant.
  • Visual pigments are found in specialized retinal cells at the back of the eye.
  • The technique is not suitable for blindness caused by retinal damage.
  • Others want to deliver working copies of broken genes into retinal cells, restoring their function.
  • At some point, they leave this cycle and commit to becoming one of the various types of retinal cells.
  • The drops protected the animals' retinal ganglion cells and optic nerves, both of which are generally damaged by the disease.
  • He extracted retinal tissue from amphibians and exposed the living tissue to a series of simple geometric patterns.
  • The action of a photon on a rhodopsin molecule in a retinal cell has some quantum mechanical interpretations, and so forth.
  • Maps are made by surveyors who record pointer readings, not retinal images.
British Dictionary definitions for retinal


the aldehyde form of the polyene retinol (vitamin A) that associates with the protein opsin to form the visual purple pigment rhodopsin
Word Origin
C20: from retina + -ene
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition
© William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins
Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Cite This Source
Word Origin and History for retinal

1838; see retina + -al (1).

Online Etymology Dictionary, © 2010 Douglas Harper
Cite This Source
retinal in Medicine

retinal ret·i·nal (rět'n-āl', -ôl')
See retinaldehyde.

The American Heritage® Stedman's Medical Dictionary
Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Cite This Source

Word of the Day

Difficulty index for retinal

Many English speakers likely know this word

Word Value for retinal

Scrabble Words With Friends