a. Imitating, esp. in derision, or so as to cause derision; mimicking; derisive. [ 1913 Webster ]

Mocking thrush (Zool.), any species of the genus Harporhynchus, as the brown thrush (Harporhynchus rufus). --
Mocking wren (Zool.), any American wren of the genus Thryothorus, esp. Thryothorus Ludovicianus. [ 1913 Webster ]

n. (Zool.), A long-tailed gray-and-white songbird of North America (Mimus polyglottos), remarkable for its exact imitations of the notes of other birds. Its back is gray; the tail and wings are blackish, with a white patch on each wing; the outer tail feathers are partly white. Originally its range was confined mostly to the southern states, but by late 19th century it had migrated as far north as New York. The name is also applied to other members of thee same and related genera, found in Mexico, Central America, and the West Indies, such as the blue mockingbird of Mexico, Melanotis caerulescens.
Syn. -- mocker, Mimus polyglottos . [ WordNet 1.5 ]

adv. By way of derision; in a contemptuous or mocking manner. [ 1913 Webster ]

n. A butt of sport; an object of derision. [ R. ] [ 1913 Webster ]