Find the word definition

Wiktionary
caveolae

n. (plural of caveola English)

Wikipedia
Caveolae

In biology, caveolae ( Latin for "little caves"; singular, caveola), which are a special type of lipid raft, are small (50–100 nanometer) invaginations of the plasma membrane in many vertebrate cell types, especially in endothelial cells and adipocytes.

These flask-shaped structures are rich in proteins as well as lipids such as cholesterol and sphingolipids and have several functions in signal transduction. They are also believed to play a role in endocytosis, oncogenesis, and the uptake of pathogenic bacteria and certain viruses.