Webster's Revised Unabridged Dictionary · 1913

Tighten

Tighten , transitive verb

To draw tighter; to straiten; to make more close in any manner.
Just where I please, with tightened rein I'll urge thee round the dusty plain. — Fawkes
Collocations (1)
Tightening pulley (Machinery) , a pulley which rests, or is forced, against a driving belt to tighten it.