epithelial

American  

[ep-uh-thee-lee-uhl] / ˌɛp əˈθi li əl /

adjective

1. Biology. being or relating to an epithelium, any tissue that lines a cavity or covers a surface in an animal or plant.

   Cheek epithelial cells are often studied in school labs as they are easily obtained through a mouth rinse or swab.

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Other Word Forms

• interepithelial adjective
• nonepithelial adjective
• subepithelial adjective
• unepithelial adjective

Etymology

Origin of epithelial

First recorded in 1935–40; epitheli(um) ( def. ) + -al ¹ ( def. )

Example Sentences

In a study published in Cell Stem Cell, scientists tested retinal pigment epithelial stem cells in a phase 1/2a clinical trial.

From Science Daily • Nov. 22, 2025

This limitation is crucial, he added, because the interior of each cyst -- essentially a sealed chamber lined with epithelial cells -- is the location where disease-driving activity occurs.

From Science Daily • Nov. 19, 2025

These include hormonal cancers like uterine cancer, as well as epithelial cancers, such as some types of liver cancer.

From Salon • Jan. 24, 2025

A preprint out this week indicates currently circulating clade 2.3.4.4b viruses are better at binding to human epithelial cells in the airways than previous versions of H5N1.

From Science Magazine • Dec. 5, 2024

Most cervical cancers are carcinomas, which grow from the epithelial cells that cover the cervix and protect its surface.

From "The Immortal Life of Henrietta Lacks" by Rebecca Skloot