The word "normal brake" can be replaced by a few different synonyms depending on the context. The most commonly used synonym is "conventional brake," which refers to a traditional braking system found in most cars. Another synonym is "standard brake" which is also used to denote a basic, unmodified braking system. In more technical terms, the term "friction brake" may also be used to describe a normal brake, as it relies on the friction between the brake pads and the rotor to slow down a vehicle. However, it's important to note that in some contexts, the term "normal brake" may simply refer to the expected or usual behavior of a brake system, rather than a specific type of brake.