photosynthesis
noun
pho·to·syn·the·sis ˌfō-tō-ˈsin(t)-thə-səs 
: synthesis of chemical compounds with the aid of radiant energy and especially light
especially : formation of carbohydrates from carbon dioxide and a source of hydrogen (such as water) in the chlorophyll-containing cells (as of green plants) exposed to light
photosynthesize
ˌfō-tō-ˈsin(t)-thə-ˌsīz
intransitive verb photosynthetic
ˌfō-tō-sin-ˈthe-tik
adjective photosynthetically
ˌfō-tō-sin-ˈthe-ti-k(ə-)lē
adverb 
Did you know?
Photosynthesis Has Greek Roots
The Greek roots of photosynthesis combine to produce the basic meaning "to put together with the help of light". Photosynthesis is what first produced oxygen in the atmosphere billions of years ago, and it's still what keeps it there. Sunlight splits the water molecules (made of hydrogen and oxygen) held in a plant's leaves and releases the oxygen in them into the air. The leftover hydrogen combines with carbon dioxide to produce carbohydrates, which the plant uses as food—as do any animals or humans who might eat the plant.
Example Sentences
Recent Examples on the Web Eventually, the root will starve and die from lack of photosynthesis. 
oregonlive, 7 Aug. 2022 Robert Jinkerson, a professor at the University of California, Riverside, looked at the lackluster efficiency of photosynthesis and saw an engineering problem. Wired, 5 July 2022 Green plants get the energy to grow from the sun through the process of photosynthesis. Steven Savage, Forbes, 25 Apr. 2022 The bugs also release a sticky, sugary waste product called honeydew, per the Guardian, which attracts sooty molds that can interfere with plant photosynthesis. Will Sullivan, Smithsonian Magazine, 17 Aug. 2022 Even plants respire, in a process separate from photosynthesis; animals such as jellyfish or earthworms, which lack respiratory systems, breathe through their skin. Brooke Jarvis, The New Yorker, 18 Jan. 2021 In return, the algae make food for the polyps through photosynthesis. Lela Nargi, Washington Post, 16 Aug. 2022 Life on Earth has drastically changed its atmosphere, mainly through photosynthesis, in ways that ordinary chemistry might find hard to mimic. Frank Wilczek, WSJ, 30 July 2022 Ocean oddities called mixoplankton are organisms that can get energy both through photosynthesis and by eating other microbes. Susan Cosier, Scientific American, 19 May 2022 See More
oregonlive, 7 Aug. 2022 Robert Jinkerson, a professor at the University of California, Riverside, looked at the lackluster efficiency of photosynthesis and saw an engineering problem. Wired, 5 July 2022 Green plants get the energy to grow from the sun through the process of photosynthesis. Steven Savage, Forbes, 25 Apr. 2022 The bugs also release a sticky, sugary waste product called honeydew, per the Guardian, which attracts sooty molds that can interfere with plant photosynthesis. Will Sullivan, Smithsonian Magazine, 17 Aug. 2022 Even plants respire, in a process separate from photosynthesis; animals such as jellyfish or earthworms, which lack respiratory systems, breathe through their skin. Brooke Jarvis, The New Yorker, 18 Jan. 2021 In return, the algae make food for the polyps through photosynthesis. Lela Nargi, Washington Post, 16 Aug. 2022 Life on Earth has drastically changed its atmosphere, mainly through photosynthesis, in ways that ordinary chemistry might find hard to mimic. Frank Wilczek, WSJ, 30 July 2022 Ocean oddities called mixoplankton are organisms that can get energy both through photosynthesis and by eating other microbes. Susan Cosier, Scientific American, 19 May 2022 See More Word History
Etymology
New Latin
First Known Use
1898, in the meaning defined above
Kids Definition
photosynthesis
noun
pho·to·syn·the·sis ˌfō-tə-ˈsin-thə-səs
: the process by which green plants and a few other organisms (as some protists) form carbohydrates from carbon dioxide and water in the presence of light
Medical Definition
photosynthesis
noun
pho·to·syn·the·sis ˌfōt-ō-ˈsin(t)-thə-səs
plural photosyntheses
: synthesis of chemical compounds with the aid of light sometimes including the near infrared or near ultraviolet
especially : the formation of carbohydrates from carbon dioxide and a source of hydrogen (as water) in chlorophyll-containing cells (as of green plants) exposed to light involving a photochemical release of oxygen through the decomposition of water followed by various enzymatic synthetic reactions that usually do not require the presence of light