'asepalous' originates from 'Greek' and 'Neo-Latin', specifically the prefix 'a-' (from Greek) meant 'without' and the Neo-Latin word 'sepalum' meant 'sepal'.

'asepalous' was formed in modern botanical English by combining the Greek prefix 'a-' with Neo-Latin 'sepalum' and the English adjectival suffix '-ous', producing the adjective used in botanical descriptions.

Initially, it meant 'without sepals', and over time this technical botanical meaning has remained essentially the same in modern usage.