Brechtian Cluster

The Brechtian Cluster was a star cluster that was located somewhere in the Alpha or Beta Quadrant. This cluster contained two inhabited planets.

In 2368, all life on those planets were threatened by the Crystalline Entity. The USS Enterprise-D was able to intercept the Entity before it reached the Brechtian Cluster. (TNG: "Silicon Avatar")

The Star Trek Encyclopedia, 4th ed., vol. 1, p. 102 identified the Brechtian Cluster as a star system.
"Brechtian" was a word refering to the literary style of Bertolt Brecht