What you likely mean is "deodorant" or "antiperspirant."
* Deodorant masks the odor of sweat. It does not reduce sweating.
* Antiperspirant reduces sweating by blocking sweat glands. It often also contains deodorant to mask any remaining odor.
If you're interested in the physiological meaning of perspiration, that simply refers to the process of sweating.
Let me know if you have any other questions!