conspire
1. [ verb ] engage in plotting or enter into a conspiracy, swear together
Synonyms: complot conjure machinate cabal
Examples:

"They conspired to overthrow the government"

Related terms: plot coconspire conspiracy intrigue conspirator
2. [ verb ] (law) act in unison or agreement and in secret towards a deceitful or illegal purpose
Synonyms: collude
Examples:

"The two companies conspired to cause the value of the stock to fall"

Related terms: interact connivance
Similar spelling:   conspirator
  conspiracy
  conspectus
  conspicuous
  conspecific
  Conospermum