sidereus

Latin

sīdus (“a star”, “a constellation”, stem: sīder-) +‎ -eus (suffix forming adjectives from nouns)

sīdereus (feminine sīderea, neuter sīdereum); first/second-declension adjective

of, pertaining to, or consisting of a stellar object or objects
1. of or belonging to the stars
  1. full of stars, starry
2. of or belonging to the stellar constellations
3. of or belonging to the Sun
(transferred senses):
1. like a star or the stars in terms of beauty, brightness, brilliance, magnitude, majesty, etc.
2. (in general) bright, glittering, shining, excellent, shiny, sparkling
3. (poetic, especially of heroes or the gods) heavenly, divine, brilliant

First/second-declension adjective.

	masculine	feminine	neuter	masculine	feminine	neuter
	singular			plural
nominative	sīdereus	sīderea	sīdereum	sīdereī	sīdereae	sīderea
genitive	sīdereī	sīdereae	sīdereī	sīdereōrum	sīdereārum	sīdereōrum
dative	sīdereō	sīdereae	sīdereō	sīdereīs
accusative	sīdereum	sīdeream	sīdereum	sīdereōs	sīdereās	sīderea
ablative	sīdereō	sīdereā	sīdereō	sīdereīs
vocative	sīderee	sīderea	sīdereum	sīdereī	sīdereae	sīderea

“sīdĕrĕus”, in Charlton T. Lewis and Charles Short (1879) A Latin Dictionary, Oxford: Clarendon Press
“sidereus”, in Charlton T. Lewis (1891) An Elementary Latin Dictionary, New York: Harper & Brothers
sīdĕrĕus in Gaffiot, Félix (1934) Dictionnaire illustré latin-français, Hachette, page 1,438.
“sīdereus” on page 1,756/2 of the Oxford Latin Dictionary (1st ed., 1968–82)