trophoblast

noun

tro·​pho·​blast ˈtrō-fə-ˌblast 

: the outer layer of the mammalian blastocyst that supplies nutrition to the embryo and facilitates implantation

trophoblastic

ˌtrō-fə-ˈbla-stik 

adjective

Examples of trophoblast in a Sentence

Recent Examples on the Web

In 2018, the first placental organoids were grown from trophoblasts – cells found only in the placenta. —Neetika Walter, Interesting Engineering, 15 Sep. 2025

Its hollow shell is made of cells that will form the placenta (called trophoblast stem cells, or TSCs) and the yolk sac (the extra-embryonic endoderm, or XEN cells). —Philip Ball, Quanta Magazine, 13 June 2023

Less than a week after a sperm fertilizes an egg, specialized cells called trophoblasts emerge on the surface of the embryo. —Adrian Erlebacher, Scientific American, 1 Oct. 2017

Word History

Etymology

International Scientific Vocabulary

First Known Use

1889, in the meaning defined above

Rhymes for trophoblast

• chloroplast
• epiblast
• opencast
• overcast
• protoplast
• rebroadcast
• telecast
• ultrafast
• unsurpassed
• aghast
• amassed
• biassed

Medical Definition

trophoblast

noun

tro·​pho·​blast ˈtrō-fə-ˌblast 

: the outer layer of the mammalian blastocyst that supplies nutrition to the embryo, facilitates implantation by eroding away the tissues of the uterus with which it comes in contact allowing the blastocyst to sink into the cavity formed in the uterine wall, and differentiates into the extraembryonic membranes surrounding the embryo

called also trophoderm

trophoblastic

ˌtrō-fə-ˈblas-tik 

adjective