From The Collaborative International Dictionary of English v.0.48 :
Brown thrush \Brown" thrush"\ (Zool.)
A common American singing bird ({Harporhynchus rufus),
allied to the mocking bird; -- also called brown thrasher.
[1913 Webster]
From WordNet (r) 3.0 (2006) :
brown thrush
n 1: common large songbird of eastern United States having
reddish-brown plumage [syn: brown thrasher, brown
thrush, Toxostoma rufums]