'astrochemistry' is a compound formed from the combining form 'astro-' (from Greek 'astron' meaning 'star') and 'chemistry' (from Medieval Latin/Old French roots related to 'alchemy' and 'khemia').

'astro-' comes from Greek 'astron' meaning 'star'; 'chemistry' developed from late Latin/Medieval Latin 'alchimia' (through Old French) into modern English 'chemistry'. The modern compound 'astrochemistry' arose in the 20th century as the study of chemical processes in space became established.

Initially the parts meant 'star' and (through 'alchemy') 'chemical art' or 'substances'; combined in the 20th century to denote the scientific field 'chemistry of astronomical environments' rather than mystical practice.