intransitive. To combine in action or aim; to act in purposive combination, union, or harmony.

To combine in action, to co-operate. of things, causes, circumstances, conditions.

intransitive. To work together, act in conjunction (with another person or thing, to an end or… Of things: To concur in producing an effect.

intransitive. To work together; to co-operate.

intransitive (for reflexive). To act in combined order for the production of a particular result.

intransitive. To act cooperatively or in combination, esp. to mutual benefit; to exhibit synergy; to act as a synergist.

intransitive. To act together. rare.