1. The carrier in which a chemical reaction takes place.

2. Material of controlled pore size used to remove foreign particles or liquid droplets from fluid carriers.

The material, or configuration thereof, on which data are recorded; usually not applied to disk, drum, or core, but to storable, removable media, such as paper tape, cards, and magnetic tape.

That entity in which objects exist and phenomena take place; examples are free space and various fluids and solids.