Synonyms for Water Hen (same or very similar meaning)
WordNet sense 1 (a coot found in North America):
American coot, Fulica americana, marsh hen, mud henWordNet sense 2 (any of various small aquatic birds of the genus Gallinula distinguished from rails by a frontal shield and a resemblance to domestic hens):
gallinule, swamphenFrom the ODE community, based on WordNetadd/edit