Dictionary definition for: Stiffen
1. (v) become stiff or stiffer; "He stiffened when he saw his boss enter the room"
2. (v) make stiff or stiffer; "Stiffen the cream by adding gelatine"
3. (v) restrict; "Tighten the rules" "stiffen the regulations"
WordNet 2.1 Copyright Princeton University. All rights reserved.
