- something filled with, a container or box for, e.g. inko ink, inkujo ink-pot.
- (only official) a country inhabited by, or associated with, an ethnic group, e.g. turko Turk, Turkujo Turkey.
- (obsolete) a tree bearing a fruit, e.g. pomo apple, pomujo apple tree.
The differences between -uj- and -ing- are subtle. An -ing- generally contains part of an object (generally an extremity) to fix it in place, such as a glavingo (“scabbard”) or plumingo (“pen holder”), whereas an -uj- is generally a container for something you replenish or keep in quantity, usually containing things in their entriety, such as a cigarujo (“cigar box”) or sukerujo (“sugar bowl”).
-uj- is almost never used for names of fruit trees outside of early Esperanto writings. This archaic usage comes directly from the Fundamento de Esperanto, but has been nearly entirely supplanted by compounds ending in arbo (“tree”) or arbusto (“bush”), such as pomarbo (“apple tree”).
Some countries in Europe and Asia have Esperanto names using -uj-. These names, though less used, are still the sole official forms.