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1. Restraint that attaches to something or holds something in place
   - fastener, holdfast, fixing
    
2. The act of fastening things together
   - attachment

1. Cause to be firmly attached
   "fasten the lock onto the door";
   - fix, secure
    
2. Become fixed or fastened
   "This dress fastens in the back"
    
3. Attach to
   "They fastened various nicknames to each other"
    
4. Make tight or tighter
   "fasten the wire";
   - tighten

Derived forms: fastenings

Type of: alter, attach, change, connection, connexion [Brit], constraint, joining, modify, restraint

Antonym: unfasten

Encyclopedia: Fastening