- related in an unspecific way. A lexical suffix with no fixed meaning or part of speech.
Usage notes 
Because meanings of words derived with this suffix cannot be predicted, each derivation requires a separate dictionary entry. The part of speech is specific to each coining, and not inherent in either the suffix or the stem to which it is attached.
Among other uses:
- With body parts, -um- may signify a related piece of clothing: kolumo, manumo, plandumo, nazumo, hufumo. Or it may signify an action using that body part: brakumi, palpebrumi, okulumi.