n. 1 low land flooded in wet weather and usu. watery at all times. 2 (attrib.) of or inhabiting marshland. marsh fever malaria. marsh gas methane. marsh-harrier a European harrier, Circus aeruginosus (see HARRIER(3)). marsh mallow a shrubby herbaceous plant, Althaea officinalis, the roots of which were formerly used to make marshmallow. marsh marigold a golden-flowered ranunculaceous plant, Caltha palustris, growing in moist meadows etc.: also called KINGCUP. marsh tit a grey tit, Parus palustris, inhabiting marshland. marsh trefoil the buckbean. marshy adj. (marshier, marshiest). marshiness n.
[ OE mer(i)sc f. WG ]