To form or gather into a mass or whole. To form into or merge with a corporate conglomerate. A corporation made up of a number of different companies that operate in diversified fields. A collected heterogeneous mass; a cluster: a conglomerate of color, passion, and artistry. Geology A coarse-grained sedimentary rock consisting of rounded to subangular rock fragments cemented together by hardened silt, clay, calcium carbonate, or similar material. Gathered into a mass; clustered. Geology Made up of loosely cemented heterogeneous material.