an animal tissue consisting of one or more layers of closely packed cells covering the external and internal surfaces of the body. The cells vary in structure according to their function, which may be protective, secretory, or absorptive
Derived forms
epithelial (ˌepiˈthelial)
adjective
Word origin
C18: New Latin, from epi- + Greek thēlē nipple
epithelium in American English
(ˌɛpɪˈθiliəm)
nounWord forms: pluralˌepiˈtheliums or ˌepiˈthelia (ˌɛpɪˈθiliə)
cellular tissue covering external body surfaces, as the epidermis, or lining internal surfaces, as hollow organs, vessels, etc.: it consists of one or more layers of cells with little intercellular material