The Collaborative International Dictionary of English v.0.48:

Apery \Ap"er*y\, n.; pl. Aperies.
   1. A place where apes are kept. [R.] --Kingsley.
      [1913 Webster]

   2. The practice of aping; an apish action. --Coleridge.
      [1913 Webster]

WordNet (r) 3.0 (2006):

apery
    n 1: the act of mimicking; imitative behavior [syn: apery,
         mimicry]