chlorophyll

noun

chlo·​ro·​phyll ˈklȯr-ə-ˌfil How to pronounce chlorophyll (audio)
-fəl
1
: the green photosynthetic pigment found chiefly in the chloroplasts of plants and occurring especially as a blue-black ester C55H72MgN4O5 or a dark green ester C55H70MgN4O6

called also respectively chlorophyll a, chlorophyll b

2
: a waxy green chlorophyll-containing substance extracted from green plants and used as a coloring agent or deodorant
chlorophyllous adjective

Examples of chlorophyll in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
When temperatures drop and the days get shorter, trees get less sunlight, causing the energy-absorbing chlorophyll, which gives them their green hues, to break down and reveal the other color pigments. Simmone Shah, Time, 25 Sep. 2025 As days shorten and temperatures drop, photosynthesis slows and chlorophyll — the pigment that makes leaves green — fades. Hayleigh Evans, AZCentral.com, 25 Sep. 2025 As the amount of daylight gets shorter in the fall, chlorophyll production in leaves slows down and eventually stops. Elissa Robinson, Freep.com, 22 Sep. 2025 These issues cause a drop in chlorophyll production earlier than normal, which unfortunately means a duller color show and an earlier leaf drop. Patricia Shannon, Southern Living, 21 Sep. 2025 See All Example Sentences for chlorophyll

Word History

Etymology

French chlorophylle, from chlor- + Greek phyllon leaf — more at blade

First Known Use

1819, in the meaning defined at sense 1

Time Traveler
The first known use of chlorophyll was in 1819

Browse Nearby Words

Cite this Entry

“Chlorophyll.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/chlorophyll. Accessed 2 Oct. 2025.

Kids Definition

chlorophyll

noun
chlo·​ro·​phyll ˈklōr-ə-ˌfil How to pronounce chlorophyll (audio)
ˈklȯr-,
-fəl
: the green coloring matter that is found chiefly in the chloroplasts of plants and is necessary for photosynthesis

Medical Definition

chlorophyll

noun
chlo·​ro·​phyll ˈklōr-ə-ˌfil, ˈklȯr-, -fəl How to pronounce chlorophyll (audio)
1
: the green photosynthetic coloring matter of plants found in chloroplasts and made up chiefly of a blue-black ester C55H72MgN4O5 and a dark green ester C55H70MgN4O6

called also respectively chlorophyll a, chlorophyll b

2
: a waxy green chlorophyll-containing substance extracted from green plants and used as a coloring agent or deodorant
chlorophyllous adjective
also chlorophyllose

More from Merriam-Webster on chlorophyll

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