
v. t. [ 1st pref. un- + tighten. ] To make less tight or tense; to loosen. [ 1913 Webster ]
v. t.
Just where I please, with tightened rein
I'll urge thee round the dusty plain. Fawkes. [ 1913 Webster ]
Tightening pulley (Mach.),
n. That which tightens; specifically (Mach.), a tightening pulley. [ 1913 Webster ]