'ascosporous' originates from New Latin, specifically the word 'ascospora' (formed from Greek 'askos' meaning 'bag, sac' and Greek 'spora' meaning 'seed, spore'), combined with the English adjectival suffix '-ous' meaning 'having or full of'.

'ascosporous' developed in scientific Latin/English usage by combining 'ascus' (from Greek 'askos') + 'spora' and adding the English suffix '-ous'; the term entered modern mycological English in the 19th–20th century to describe fungi that bear ascospores.

Initially it was a descriptive scientific formation meaning 'of or pertaining to ascospores'; over time it has retained this specific biological sense of 'bearing or producing ascospores' in modern usage.