A sedimentary rock composed of large chunks of other rocks cemented together is called a conglomerate.

Here's a breakdown:

* Conglomerate: A clastic sedimentary rock composed of rounded gravel-sized fragments (larger than 2 mm).

* Breccia: A similar rock but with angular fragments.

* Clastic: A type of sedimentary rock formed from fragments of other rocks.

The cementing material that binds the fragments together can be calcite, quartz, iron oxides, or other minerals.