The Collaborative International Dictionary of English v.0.48:

Stipulate \Stip"u*late\, v. i. [imp. & p. p. Stipulated; p.
   pr. & vb. n. Stipulating.] [L. stipulatus, p. p. of
   stipulari to stipulate, fr. OL. stipulus firm, fast; probably
   akin to L. stipes a post. Cf. Stiff.]
   To make an agreement or covenant with any person or company
   to do or forbear anything; to bargain; to contract; to settle
   terms; as, certain princes stipulated to assist each other in
   resisting the armies of France.
   [1913 Webster]