Entry 1 sense Webster, 1913 Wallachian · Wal·la·chi·an · IPA /wɒlˈeɪ.kiː.ən/ 01 a. Of or pertaining to Wallachia, a former principality, now part of the kingdom, of Roumania. 1. Of or pertaining to Wallachia, a former principality, now part of the kingdom, of Roumania.