lunar

the word 'lunar' descends directly from the latin adjective 'lunaris', which itself is derived from 'luna', the latin word for the moon. the latin 'luna' is believed to have roots in the proto-indo-european base 'leuksna-', which is related to light, from the root 'leuk-' meaning 'light' or 'brightness', reflecting the moon's role as a celestial source of light. the suffix '-ar' is a common latin adjectival formative, used to create adjectives meaning 'of or pertaining to'. thus, the literal construction 'pertaining to the moon' has remained semantically stable from its ancient origins to its modern scientific and poetic usage in english.

Structure: lun (moon) + ar (adjective suffix) lun (from latin 'luna', meaning 'moon'); ar (a latin adjectival suffix meaning 'pertaining to' or 'of the kind of').