'astrobotany' originates from modern English as a compound of the Greek-derived prefix 'astro-' (from Greek 'astron', meaning 'star') and 'botany' (from Greek 'botanē', meaning 'plant', via Late Latin 'botanica').

'botany' changed from Late Latin 'botanica' and Greek 'botanē' through Medieval/Latin and Middle English forms (e.g. Old French/Latin influences) to become the modern English 'botany'; 'astrobotany' is a modern English compound formed by combining 'astro-' + 'botany' in the 20th century as space science developed.

Initially, 'botany' referred broadly to 'plants' or the study of plants; over time it became the scientific discipline 'the study of plants'. 'Astrobotany' has taken the specialised modern meaning 'the study of plants in space or extraterrestrial contexts.'