Threce
Could not find Threïcius in Logeion dictionaries. Looking for closest alphabetic form.
Thrēcē, ēs, v. Thracia.
Thrēcē, ēs, f., s. Thrāces.
Thrēcē, ēs, f. (Θρῄκη), c. Thraca : Ov. Ars 2, 588 ; M. 7, 223.