A concrete margin along the edge of a road; a kerb (UK, Australia, New Zealand)
"The driver carefully guided the car up to the curb before pulling over to pick up the passenger."
In plain English: A curb is the low edge of concrete that separates a sidewalk from a street to keep people and cars apart.
"The horse reared up and hit its head on the curb before slowing down."
Usage: As a noun, curb refers to the raised stone or concrete edge at the side of a street that separates it from the sidewalk. When used as a verb, it means to restrict or limit something, such as spending habits or emotions.
Verb
1
lessen the intensity of; temper; hold in restraint; hold or keep within limits
The word curb comes from the Old French courbe, meaning "curved," which itself was borrowed from the Latin curvus. Originally referring to anything that is bent or crooked, it entered English as a doublet of the modern verb "curve."