- stiffened - made or become difficult to move or bend; "felt the pain of stiffened joints"
 Antonyms: flexible, flexile (indirect, via inflexible)
 
- stiffened - stiffened or reinforced with wire; "stiffened brassieres"
 Antonym: wireless (indirect, via wired)
 
- stiffen - become stiff or stiffer; "He stiffened when he saw his boss enter the room"
 --1 is one way to change
 Antonyms: loosen, relax, loose
 
 Sample sentences:Derived form: noun stiffening1 
 Something ----s
 Somebody ----s
 
- stiffen - make stiff or stiffer; "Stiffen the cream by adding gelatine"
 --2 is one way to change, alter, modify
 Antonyms: loosen, loose
 
 Sample sentences:Derived forms: noun stiffener1, noun stiffening2 
 Somebody ----s something
 Something ----s something
 
- stiffen, tighten, tighten up, constrain - restrict; "Tighten the rules"; "stiffen the regulations"
 --3 is one way to restrict, restrain, trammel, limit, bound, confine, throttle
 Sample sentence:
 Somebody ----s something