A plural form or collection of things related to comets, though this appears to be a highly specialized or archaic term.
Potentially formed from Latin 'cometa' (comet) plus Latin plural/collective suffix '-aria', though this term is extremely rare and may be restricted to specialized astronomical or historical texts.
Some words are so specialized that they live almost invisibly in academic literature—this one seems to exist mainly as a theoretical plural form that rarely gets used in practice.
Complete word intelligence in one call. Free tier — 50 lookups/day.