The Collaborative International Dictionary of English v.0.48:

Preconcerted \Pre`con*cert"ed\, a.
   Previously arranged; agreed upon beforehand. --
   Pre`con*cert"ed*ly, adv. -- Pre`con*cert"ed*ness, n.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Preconcert \Pre`con*cert"\, v. t. [imp. & p. p. Preconcerted;
   p. pr. & vb. n. Preconcerting.]
   To concert or arrange beforehand; to settle by previous
   agreement.
   [1913 Webster]

WordNet (r) 3.0 (2006):

preconcerted
    adj 1: previously arranged or agreed on; "following preconcerted
           plans"