A New World warbler, Oporornis (or Geothlypis) philadelphia (family Parulidae), of Canada and the north-eastern United States, with a grey head and breast and yellow underparts.
Origin
Early 19th century; earliest use found in Alexander Wilson (1766–1813), ornithologist and poet.
Definition of mourning warbler in US English:
mourning warbler
noun
A New World warbler, Oporornis (or Geothlypis) philadelphia (family Parulidae), of Canada and the north-eastern United States, with a grey head and breast and yellow underparts.
Origin
Early 19th century; earliest use found in Alexander Wilson (1766–1813), ornithologist and poet.