Entry 2 senses · 2 variants Webster, 1913 Oscinian · Os·cin·i·an · IPA n. n. 01 n. One of the Oscines, or singing birds. 1. One of the Oscines, or singing birds.(Zool.) 02 n. Any one of numerous species of dipterous flies of the family Oscinidae. 1. Any one of numerous species of dipterous flies of the family Oscinidae.(Zool.)