The Collaborative International Dictionary of English v.0.48:
Mocking \Mock"ing\, 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] mockingbird