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photoperiod

[ foh-tuh-peer-ee-uhd ]
/ ˌfoʊ təˈpɪər i əd /
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noun Biology.

the interval in a 24-hour period during which a plant or animal is exposed to light.

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Origin of photoperiod

First recorded in 1915–20; photo- + period
pho·to·pe·ri·od·ic [foh-tuh-peer-ee-od-ik], /ˌfoʊ təˌpɪər iˈɒd ɪk/, pho·to·pe·ri·od·i·cal, adjectivepho·to·pe·ri·od·i·cal·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for photoperiod

photoperiod
/ (ˌfəʊtəʊˈpɪərɪəd) /

noun

the period of daylight in every 24 hours, esp in relation to its effects on plants and animalsSee also photoperiodism
photoperiodic, adjectivephotoperiodically, adverb
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

Medical definitions for photoperiod

photoperiod
[ fō′tō-pîrē-əd ]

n.

The duration of an organism's daily exposure to light, considered especially with regard to the effect of such exposure on growth and development.
pho′to•pe′ri•odic (-ŏdĭk) null adj.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

Scientific definitions for photoperiod

photoperiod
[ fō′tō-pîrē-əd ]

The duration of an organism's daily exposure to light, considered especially with regard to the phenomena of photoperiodism.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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