purple avens n 1: North American perennial with hairy basal pinnate leaves and purple flowers and plume-tipped fruits [syn: {prairie smoke}, {Geum triflorum}] 2: erect perennial of north temperate zone having pinnate leaves and few nodding flowers with brown-purple calyx and orange-pink petals [syn: {water avens}, {Indian chocolate}, {chocolate root}, {Geum rivale}]