Camber

A slight convex curve of a surface, such as in a prestressed concrete deck.

Merriam-Webster Online Dictionary
camber (verb)
intransitive verb
transitive verb
to curve upward in the middle
1.
to arch slightly
2.
to impart camber to
camber (noun)
1.
a slight convexity, arching, or curvature (as of a beam, deck, or road)
2.
the convexity of the curve of an airfoil from the leading edge to the trailing edge
3.
a setting of the wheels of an automotive vehicle closer together at the bottom than at the top