a board with wheels that is ridden in a standing or crouching position and propelled by foot
"The young boy pushed off the curb to propel his skateboard down the sidewalk while balancing carefully."
A narrow, wooden or plastic platform mounted on pairs of wheels, on which one stands and propels oneself by pushing along the ground with one foot.
"The children lined up to ride their skateboards down the smooth concrete ramp at the local park."
In plain English: A skateboard is a small board with four wheels that you stand on and push to ride around.
"The teenager rode his skateboard down the sidewalk to school."
Usage: Do not confuse "skateboard" as a verb; use "to skateboard" instead when describing the action. In formal writing, prefer "longboard" or describe the activity explicitly rather than using the noun metonymically to refer to the rider.
ride on a flat board with rollers attached to the bottom
"The young man learned how to skateboard down the smooth pavement before heading home."
To use a skateboard.
"The kids rode their skateboards down the smooth concrete ramp."
The word skateboard is a straightforward combination of the words skate and board that emerged to describe the wheeled recreational device. It was formed by joining these two existing terms to create a new name for this specific piece of equipment.