scientific word-forming element meaning "gland," from Greek adēn "gland," which is perhaps from a suffixed form of PIE root *engw- "groin; internal organ" (source also of Latin inguen "groin"), but Beekes rejects all cognates and calls it isolated.
Entries linking to adeno-
adenine n.
crystalline base, 1885, coined by German physiologist/chemist Albrecht Kossel from Greek adēn "gland" (see adeno-) + chemical suffix -ine (2). So called because it was derived from the pancreas of an ox.
adenoid adj.
1839, "gland-like," from medical Latin adenoideus, from Greek adenoeides, from adēn (genitive adēnos) "gland" (see adeno-) + eidos "form" (see -oid). Adenoids (n.) "adenoid growths" is attested by 1856.