[ foh-toh ]
See synonyms for photo on
noun,plural pho·tos.

Origin of photo

First recorded in1855–60; shortened form of photograph

Other definitions for photo- (2 of 2)


  1. a combining form meaning “light” (photobiology); also used to represent “photographic” or “photograph” in the formation of compound words: photocopy.

Origin of photo-

<Greek, combining form of phôs (genitive phōtós)
  • Also especially before a vowel, phot-. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023

How to use photo in a sentence

British Dictionary definitions for photo (1 of 2)


/ (ˈfəʊtəʊ) /

nounplural -tos

British Dictionary definitions for photo- (2 of 2)


combining form
  1. of, relating to, or produced by light: photosynthesis

  2. indicating a photographic process: photolithography

Origin of photo-

from Greek phōs, phōt- light

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

Scientific definitions for photo-


  1. A prefix that means “light,” as in photoreceptor.

The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.