clientele (n.)
1560s, "body of professed adherents," from French clientèle (16c.), from Latin clientela "relationship between dependent and patron, body of clients," from clientem (nominative cliens; see client). Meaning "customers, those who regularly patronize a business or professional" is from 1857, perhaps a reborrowing from French (it was used in English in italics as a foreign word from 1836).