1. Make smaller or less in amount, degree, or size.
2. Bring someone or something to (a worse or less desirable state or condition).
3. Change a substance to (a different or more basic form).
4. Cause to combine chemically with hydrogen.
5. Restore (a dislocated part of the body) to its proper position by manipulation or surgery.
6. Besiege and capture (a town or fortress).
Verb form: Reduce, Reduced, Reduced
People must reduce the speed of the vehicles.