The portion of the ocean floor made up of oceanic crust is called the oceanic lithosphere.

Here's a breakdown:

* Oceanic Crust: This is the thin, dense, and relatively young layer of Earth's crust that underlies the ocean basins. It's primarily composed of basalt and gabbro.

* Oceanic Lithosphere: This encompasses the entire rigid layer of the Earth that includes the oceanic crust and the uppermost mantle. It's broken into tectonic plates that move and interact.

Essentially, the oceanic lithosphere is the entire rigid section of the Earth that makes up the ocean floor. This includes both the oceanic crust and the part of the upper mantle that's attached to it.