About ‘unknown’ entries

Some entries in this dictionary may have a definition that says 'unknown noun/verb', as in the following example

What does this mean?  It means that this morpheme appears in the Timucua texts with verbal morphology.  Thus we can know that it is a verb, but its meaning is not yet known.  (This is usually because the morpheme of uncertain meaning does not appear frequently enough to be sure of its meaning.)