The roots of this plant were collected in Elizabethan times for their high starch content, which was used to stiffen fashionable linen ruffs.
There is also in large bridges wind-bracing to stiffen the structure against horizontal forces.
The barbs possess further branches called the barbules, and adjacent barbules are attached to one another by hooks which stiffen the vane.
As a child grows the eustachian tubes widen and stiffen, allowing air to enter and fluid to drain from the middle ear more efficiently.
In the case of the plate web there must be a considerable excess of material, partly to stiffen it against buckling and partly because an excess of thickness must be provided to reduce the effect of corrosion.