Source : Webster's Revised Unabridged Dictionary (1913)

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.

Preconcerted \Pre`con*cert"ed\, a.
   Previously arranged; agreed upon beforehand. --
   {Pre`con*cert"ed*ly}, adv. -- {Pre`con*cert"ed*ness}, n.

Source : WordNet®

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