'angulate-veined' is a Modern English compound formed from 'angulate' and 'veined'. 'angulate' originates from Latin, specifically the Medieval/Modern Latin adjective 'angulatus', where 'angulus' meant 'angle'. 'veined' derives from Old French 'veine' (from Latin 'vena'), where 'vena' meant 'vein'.

'angulate' entered English via Medieval/Modern Latin 'angulatus' (from Latin 'angulus') and developed into the English adjective 'angulate'; 'vein' came into English from Old French 'veine' (from Latin 'vena'), becoming Middle English 'vein' and later the adjective form 'veined'. The compound 'angulate-veined' arose in Modern English as a descriptive botanical term.

Initially 'angulate' meant 'having angles' (from Latin 'angulus') and 'veined' meant 'having veins' (from Latin 'vena'); combined in Modern English the compound specifically denotes 'having veins that form angles' (a botanical descriptive meaning).