Entry 3 senses · 2 variants Webster, 1913 Slavonian · Sla·vo·ni·an · IPA /sləˈvoʊ.ni.ən/ a. n. 01 a. Of or pertaining to Slavonia, or its inhabitants. 1. Of or pertaining to Slavonia, or its inhabitants. 2. Of or pertaining to the Slavs, or their language. 02 n. A native or inhabitant of Slavonia; ethnologically, a Slav. 1. A native or inhabitant of Slavonia; ethnologically, a Slav.