The phrase "in cahoots with" refers to two or more people conspiring or collaborating together. There are several different synonyms for this phrase, including "in league with," "working hand in glove," "cooperating with," "in collusion with," and "conspiring with." Each of these phrases has a slightly different connotation but all suggest that the individuals involved are working together for a specific purpose. Other related phrases include "in partnership with," "in alliance with," and "in concert with." Whatever the specific phrase used, the implication is that a group of people is acting together, often in a secretive or deceitful manner.