'astrotheology' originates from Modern English, specifically the combining form 'astro-' (from Greek 'astron' meaning 'star') and 'theology' (from Greek 'theologia' meaning 'discourse about God').

'astrotheology' is formed by compounding the Greek-derived prefix 'astro-' with the English word 'theology'; both elements trace back through post-classical and medieval usage of Greek and Latin roots into modern English formation patterns.

Initially, the elements referred separately to 'stars' and 'discourse about God'; together in modern usage the compound has come to mean the theological interpretation or religious significance of the heavens or celestial phenomena.