definition of
tighten

[1] #1 tighten v. [fasten] make tight or tighter; "Tighten the wire". wn

[2] #2 tighten v. become tight or tighter; "The rope tightened". wn

[3] #3 tighten v. [stiffen, tighten up, constrain] restrict; "Tighten the rules"; "stiffen the regulations". wn

[4] #4 tighten v. [reduce] narrow or limit; "reduce the influx of foreigners". wn