black hellebore n 1: slightly hairy perennial having deep green leathery leaves and flowers that are ultimately purplish-green [syn: {lenten rose}, {black hellebore}, {Helleborus orientalis}] 2: European evergreen plant with white or purplish rose-like winter-blooming flowers [syn: {Christmas rose}, {winter rose}, {black hellebore}, {Helleborus niger}]