The cellular compartment that contains the greatest amount of body fluid is the intracellular fluid (ICF).

Here's why:

* ICF is the fluid found inside cells, making up about 67% of total body water.

* Extracellular fluid (ECF), which includes interstitial fluid (fluid surrounding cells) and plasma (fluid in blood vessels), makes up the remaining 33% of total body water.

Therefore, the ICF significantly outweighs the ECF in terms of fluid volume.