Stiffen - Definition
stiffen
v 1: become stiff or stiffer; "He stiffened when he saw his boss
enter the room" [ant: loose, loosen, relax]
2: make stiff or stiffer; "Stiffen the cream by adding gelatine"
[ant: loose, loosen]
3: restrict; "Tighten the rules"; "stiffen the regulations"
[syn: stiffen, tighten, tighten up, constrain]