1. (verb) restrict

• constrain
• tighten
• tighten up

1. (verb) become stiff or stiffer

• change

2. (verb) make stiff or stiffer

• alter
• change
• modify

3. (verb) restrict

• bound
• confine
• limit
• restrain
• restrict
• throttle
• trammel

1. (verb) become stiff or stiffer

• rigidify

2. (verb) make stiff or stiffer

• buckram
• ossify
• petrify
• rigidify
• starch

1. (verb) become stiff or stiffer

• loose
• loosen
• relax

2. (verb) make stiff or stiffer

• loose
• loosen

1. (verb) become stiff or stiffer

• stiffening

2. (verb) make stiff or stiffer

• rigidification
• rigidifying
• stiffening
• stiffener