General synonyms:
* Reciprocal: This is the most direct synonym and emphasizes the back-and-forth nature of the relationship.
* Shared: This highlights the commonality between the parties.
* Joint: This implies a combined effort or ownership.
* Common: This suggests something is held or experienced by both parties.
More specific synonyms, depending on the context:
* Bilateral: This refers to something involving two sides.
* Two-way: This emphasizes the equal exchange between parties.
* Interdependent: This implies that the parties rely on each other.
* Collaborative: This suggests that the parties work together.
* Symmetrical: This emphasizes the balanced nature of the relationship.
Informal synonyms:
* Both ways: This is a simple and informal way to say "mutual."
* On both sides: This is another informal way to emphasize the equal involvement of both parties.
The best synonym to use will depend on the specific context and the nuance you want to convey.