billet-doux
nounNAmE//ˌbɪli ˈdu//, NAmE//ˌbɪleɪˈdu//
(pl. billets-doux NAmE//ˌbɪli ˈduz//, NAmE//ˌbɪleɪˈduz//, NAmE//ˌbɪliˈdu//, NAmE//ˌbɪleɪ ˈdu//
) (from French) (humorous or )Check pronunciation: billet-doux
Definition of billet-doux noun from the Oxford Advanced American Dictionary