Definition of Old Etonian in English:
Old Etonian
noun ˌəʊld ɪˈtəʊnɪən
A former pupil of Eton College.
adjective ˌəʊld ɪˈtəʊnɪən
Designating, relating to, or characteristic of former pupils of Eton College.
Origin
Mid 18th century. From old + Etonian.