blastocyst

noun

blas·​to·​cyst ˈbla-stə-ˌsist 

: the modified blastula of a placental mammal having an outer layer composed of the trophoblast

Examples of blastocyst in a Sentence

Recent Examples on the Web

In a scene following the triumph of successfully creating a human blastocyst outside the womb, IVF’s three progenitors face the Medical Research Council. — Literary Hub, 29 Apr. 2026

For example, synthetic blastoids develop a blastocoel cavity and the three main cell types (epiblast, trophectoderm, and primitive endoderm) within one week, just like natural blastocysts. — Srishti Gupta, Interesting Engineering, 28 Mar. 2026

When sperms managed to reach the eggs, the ensuing early-stage embryos, called blastocysts, initially appeared stronger than their counterparts conceived in gravity. — Tereza Pultarova, Space.com, 27 Mar. 2026

With this defining feature, the zygote becomes a blastocyst, ready to embed itself in the lining of the uterus. — Clare Watson, Quanta Magazine, 27 Feb. 2026

Word History

Etymology

blasto- + -cyst

First Known Use

1876, in the meaning defined above

Rhymes for blastocyst

• bolshevist
• coexist
• egoist
• hedonist
• jihadist
• nativist
• oculist
• reminisced
• trotskyist
• assist
• blacklist
• booklist

Medical Definition

blastocyst

noun

blas·​to·​cyst ˈblas-tə-ˌsist 

: the modified blastula of a placental mammal