'two-leaved' originates from Old English elements 'two' (from Old English 'twa') and 'leaf' (from Old English 'lēaf'), combined with the adjectival suffix '-ed' meaning 'having'.

'two' comes from Old English 'twa' (with related forms in Proto-Germanic and Old Norse), and 'leaf' comes from Old English 'lēaf'; the compound adjective appeared in Middle English as constructions like 'two-lefed' and developed into the modern hyphenated form 'two-leaved'.

Initially it meant 'having two leaves', and this basic descriptive meaning has remained stable into modern usage.