thickness

Concise Oxford English Dictionary © 2008 Oxford University Press:
thickness/ˈθɪknəs/

▶noun

• 1 the distance through an object, as distinct from width or height.

  ■ a layer of material.

  ■ a thicker part of something.

• 2 the state or quality of being thick.

▶verb plane or cut (wood) to a desired thickness.

– derivatives
thicknesser noun.