A buttress-root.
A brick or stone structure built against another structure to support it.
Anything that supports or strengthens.
Anything that serves to support something; a prop.
A feature jutting prominently out from a mountain or rock.
To support something or someone by supplying evidence.
To support something physically with, or as if with, a prop or buttress.
The cushion of a saddle.
The person riding in the pillion.
A similar second saddle on a motorcycle for a passenger.
A pad behind the saddle of a horse for a second rider.
Riding behind the driving rider, as when positioned on the rump of a mount.
To ride on a pillion.
To put a pillion on a horse.