Which vocabulary word brst describes the thrush in The Darkling Thrush

Well in the 'Darkling Thrush' Hardy in the third stanza described the Thrush as "aged ... frail ... gaunt" and later went on to say in the said stanza that the Thrush was "a small in blast-beruffled (raggedy) plume (feather) ". In the final stanza as well Hardy described the bird metaphorically as a "terrestrial thing"

I think the answer is thrush