\Pep"per*grass`\, n. (Bot.)
(a) Any herb of the cruciferous genus {Lepidium}, especially
    the garden peppergrass, or garden cress, {Lepidium
    sativum}; -- called also {pepperwort}. All the species
    have a pungent flavor.
(b) The common pillwort of Europe ({Pilularia globulifera}).
    See {Pillwort}.