acting together with another or others
cahoots - partnership
To be in ‘cahoots’ with somebody is to be in league with them for a typically dishonest or illegal purpose. The word is always used in its plural form and preceded by the preposition ‘in’. As it implies trickery and a conspiracy directed against others for personal gain, it is almost always used in a negative context.
There’s no way that journalist could have come across all that material on her own. Somebody from within our organization must be in cahoots with her.
I didn’t stand a chance of having my contract renewed because two senior members of the management team were in cahoots against me.
The government worked in cahoots with major tech companies to push through draconian online censorship laws.