A solidarity service is a time of reflection that is similar to a Christian mass or another religious service. It is mentioned in Aldous Huxley's book, "Brave New World."
In the book, Huxley uses a solidarity service to define a religious time of reflection for the characters in the book. The author does so to enable the characters to appear religious without committing the characters to any one single religion. The religion is, instead, a time for them to contemplate their own religious beliefs and the way that they feel about the world.
While the solidarity service is meant to run on a parallel to a more traditional approach at religion, the characters of the book use it as somewhat of a mockery of traditional religious services. The characters worship the god of the book and sing hymns that are similar to hymns that are sung in traditional services. At the end of the solidarity service, the traditional church is further mocked when the participants of the service are asked to give into their earthly desires with each other. An orgy commences that would not happen in a more traditional religious world because participants are usually asked to refrain from giving into their earthly desires.