Possessed in common.
Owned by the members.
Having the same relationship, each to each other.
Collective, done or held in common.
Reciprocal.
A mutual organization.
Either of a pair of people who follow each other's social media accounts.
A mutual fund.
Considered to be of, from, or in tune with the common people, rather than from a ruling elite.
In certain socialist states: of, from, or controlled (at least in name) by the common people rather than a ruling elite.
Used other than figuratively or idiomatically: see people, -'s.