<p><strong>Noun</strong></p><ul><li>Botany, Biochemistry. The green coloring matter of leaves and plants, essential to the production of carbohydrates by photosynthesis.</li><li>Occurring in a bluish-black form, C₅₅H₇₂MgN₄O₅ (chlorophyll a), and a dark-green form, C₅₅H₇₀MgN₄O₆ (chlorophyll b).</li></ul>