Moreover, it would be found in the latter case that the bow would be much harder to bend than where the pieces were not glued together--in other words, the _stiffness_ of the bow would be materially increased.
~Stiffness~ is the property by means of which a body acted upon by external forces tends to retain its natural size and shape, or resists deformation.

Thus a material that is difficult to bend or otherwise deform is stiff; one that is easily bent or otherwise deformed is _flexible_.

Flexibility is not the exact counterpart of stiffness, as it also involves toughness and pliability.
If successively larger loads are applied to a body and then removed it will be found that at first the body completely regains its original form upon release from the stress--in other words, the body is ~elastic~.

No substance known is perfectly elastic, though many are practically so under small loads.
Eventually a point will be reached where the recovery of the specimen is incomplete.

This point is known as the ~elastic limit~, which may be defined as the limit beyond which it is impossible to carry the distortion of a body without producing a permanent alteration in shape.