English

interastral

From inter- + astral.

Proto-Indo-European *h₁én ‘in’

Proto-Indo-European *h₁entér ‘between’

Proto-Italic *n̥ter ‘between’

Latin inter ‘between’

Proto-Indo-European *h₂stḗr ‘star’

…

Ancient Greek ἀστήρ ‘star’

Ancient Greek ἄστρον ‘star’

Latin astrum ‘star’

Late Latin astrālis

Today it means

adj interstellar

Language periods are conventional ranges, not dates for this word.

Etymograph / interastral