Consider the noun "Jupiter", either the Roman god or the giant gaseous planet in our Solar System.

The adjective is "jovian", entirely unrelated.

Is this a distinct class of adjectives? I suspect there are many more examples.

EDIT: Is it possible that "Jupiter" does not have an adjective? "Jupiterian"?

In most studies for astrophysics I've seen, the go-to adjective is "Jovian"....

  • The Roman god Jupiter was also called Jove, so the adjective is highly related to the noun. The term's "happy" meaning is a result of the planet's supposed astrological influence.
    – WBT
    Aug 15, 2015 at 13:48
  • The noun and adjective may have different etymologies. An adjective is not necessarily derived from the noun. Good question, though.
    – Kris
    Aug 15, 2015 at 14:09
  • 1
    Jupiter and Jove have the same etymology. The irregularity was already present in Latin; the Ju- part of Jupiter is the same as the Jov part of Jovis, Jovem, etc. The -piter, present only on the nominative case form, just means 'father'. These are all from the same root as Zeus and other gods, PIE root *dei-. There's no special name for borrowed names that have irregular parts, btw. Aug 15, 2015 at 15:30
  • The statement 'Consider the noun N. The adjective is A, entirely [etymologically] unrelated.' does not make sense. Either it is incorrect (as here), or it should read 'Consider the noun N. There is an adjective A, entirely unrelated etymologically, meaning 'of, pertaining to, like, in some way associated with ... N.' 'The adjective' begs the question. Aug 15, 2015 at 17:21
  • The word Jovian ultimately derives from dyeus, "god", whence Deus, Zeus, Dios (in, e.g. Spanish), etc. the key thing is so does Jupiter, which is a classic Latin compound of dyeus + peter (god + father).
    – Dan Bron
    Aug 15, 2015 at 18:03

1 Answer 1


These are called collateral adjectives. You can read about them on Wikipedia and check out a list of them on Wiktionary.


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