ratchet-toothed

from The Century Dictionary.

• Having teeth which are not symmetrical on their front and back faces, but are adapted to receive and be constrained by a pawl or dog which falls into the spaces between them, so as to permit the wheel to turn in one direction, but not in the other. The front face is nearly radial and straight, while the backs are curved or inclined at an acute angle from the tangent to the wheel at the point of the tooth.