Definition of thylakoid
: any of the membranous disks of lamellae within plant chloroplasts that are composed of protein and lipid and are the sites of the photochemical reactions of photosynthesis
Origin of thylakoid
International Scientific Vocabulary thylak- (from Greek thylakos sack) + -oid
First Known Use: 1962
Learn More about thylakoid
Britannica.com: Encyclopedia article about "thylakoid"
Seen and Heard
What made you want to look up thylakoid? Please tell us where you read or heard it (including the quote, if possible).