-o (Ido) comes from Esperanto -o, from Spanish -ó, from Latin Aramaicus, from Ancient Greek Ἀραμαϊκός, from Aramaic ܐܪܡܝܐ, from Aramaic ארמיא, from Aramaic ארם — Aram (son of Shem).
-o (Ido): Nominal suffix. All Ido nouns end in -o