'many-petalled' originates from Modern English, specifically formed by combining the adjective 'many' and the adjective/participle 'petalled' (from 'petal'). 'many' ultimately comes from Old English 'manig' where 'manig' meant 'many', and 'petal' ultimately comes from Greek 'petalon' meaning 'leaf' or 'thin plate'.

'many-petalled' developed as a descriptive phrase ('many petalled') in English and later became commonly written as a hyphenated compound 'many-petalled' in modern English. The element 'petal' entered English via Latin and French from Greek 'petalon'.

Initially the root 'petalon' meant 'leaf' or 'thin plate' in Greek; over time the derived English word 'petal' came to mean the colored, leaf-like part of a flower, and 'many-petalled' therefore came to mean 'having many petals'.