WordWeb Online

1. Make loose or looser
   "loosen the tension on a rope"
   - loose
    
2. Make less severe or strict
   - relax
    
3. Become less severe or strict
   - relax
    
4. Disentangle and raise the fibers of
   - tease, tease apart
    
5. Cause to become loose
   "loosen the necktie"
   - untie, undo
    
6. Make less dense
   "loosen the soil"
    
7. Become loose or looser or less tight
   "The noose loosened"
   - relax, loose

Derived forms: loosens, loosening, loosened

See also: loosening

Type of: alter, change, disentangle, modify, straighten out, unsnarl, weaken

Antonym: stiffen