Source : Webster's Revised Unabridged Dictionary (1913)

Fastener \Fas"ten*er\, n.
   One who, or that which, makes fast or firm.

Source : WordNet®

fastener
     n 1: a person who fastens or makes fast; "he found the door
          fastened and wondered who the fastener was"
     2: restraint that attaches to something or holds something in
        place [syn: {fastening}, {holdfast}, {fixing}]