tighten


tighten (http://definr.com/tighten)

     v 1: make tight or tighter; "Tighten the wire" [syn: fasten]
     2: become tight or tighter; "The rope tightened"
     3: restrict; "Tighten the rules"; "stiffen the regulations"
        [syn: stiffen, tighten up, constrain]
     4: narrow or limit; "reduce the influx of foreigners" [syn: reduce]