The Collaborative International Dictionary of English v.0.48:
Conspire \Con*spire"\ (k[o^]n*sp[imac]r"), v. i. [imp. & p. p.
Conspired (k[o^]n*sp[imac]rd"); p. pr. & vb. n.
Conspiring.] [F. conspirer, L. conspirare to blow together,
harmonize, agree, plot; con- + spirare to breathe, blow. See
1. To make an agreement, esp. a secret agreement, to do some
act, as to commit treason or a crime, or to do some
unlawful deed; to plot together.
They conspired against [Joseph] to slay him. --Gen.
You have conspired against our royal person,
Joined with an enemy proclaimed. --Shak.
2. To concur to one end; to agree.
The press, the pulpit, and the stage
Conspire to censure and expose our age. --Roscommon.
Syn: To unite; concur; complot; confederate; league.