chlorophyll

noun

chlo·​ro·​phyll ˈklȯr-ə-ˌfil 

-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

ˌklȯr-ə-ˈfi-ləs 

adjective

Examples of chlorophyll in a Sentence

Recent Examples on the Web

The plant is suffering from photo-oxidation, where the chlorophyll is breaking down under the stress of direct UV rays. —Leanne Potts, Better Homes & Gardens, 23 Apr. 2026

Magnesium is a crucial component of chlorophyll, the compound plants use in photosynthesis. —Anyssa Roberts, The Spruce, 21 Apr. 2026

That creativity led Cochran to work with scallops in the challenge, making a duo of green and yellow sauces with broccoli and chlorophyll, daikon and a carrot and saffron broth. —Heidi Finley, Charlotte Observer, 31 Mar. 2026

The answer is that the chlorophyll pigment dominant in green leaves is more efficient at triggering photosynthesis — the process by which plants make the sugar that sustains them — than the pigments dominant in darker leaves. —Joshua Siskin, Oc Register, 28 Mar. 2026

Word History

Etymology

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

First Known Use

1819, in the meaning defined at sense 1

Kids Definition

chlorophyll

noun

chlo·​ro·​phyll ˈklōr-ə-ˌfil 

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 

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

ˌklōr-ə-ˈfil-əs, ˌklȯr- 

adjective

also chlorophyllose

-ˈfil-ˌōs, -(ˌ)fil-ˈ