The Collaborative International Dictionary of English v.0.48:

Apprentice \Ap*pren"tice\, v. t. [imp. & p. p. Apprenticed; p.
   pr. & vb. n. Apprenticing.]
   To bind to, or put under the care of, a master, for the
   purpose of instruction in a trade or business.
   [1913 Webster]

WordNet (r) 3.0 (2006):

apprenticed
    adj 1: bound by contract [syn: apprenticed, articled,
           bound, indentured]