Bacteriostatic

Etymology
Bacteriostatic:

bacterio: see bacteria static: "stopping" (from greek στατικός (statikos), meaning "causing to stand" or "stopping"). This root can also be seen in words like "static electricity", "hydrostatic pressure", "stasis", etc.

Explanation
Bacteriostatic drugs prevent bacteria (bacterio) from carrying out important functions such as protein synthesis, and normal activity, thereby stopping (static) their normal function.