Stiffen \Stiff"en\, v. t. [imp. & p. p. Stiffened; p. pr. & vb. n. Stiffening.]

[See Stiff.]

1. To make stiff; to make less pliant or flexible; as, to stiffen cloth with starch.

Stiffen the sinews, summon up the blood. --Shak.

2. To inspissate; to make more thick or viscous; as, to stiffen paste.

3. To make torpid; to benumb.

Source: Webster's Revised Unabridged Dictionary (1913)
 

Stiffening \Stiff"en*ing\, n.

1. Act or process of making stiff.

2. Something used to make anything stiff.

Stiffening order (Com.), a permission granted by the customs department to take cargo or ballast on board before the old cargo is out, in order to steady the ship.

Source: Webster's Revised Unabridged Dictionary (1913)