v. 拉紧；固定；使紧密；加严（tighten的过去式形式）

Tighten \Tight"en\, v. t. [imp. & p. p. {Tightened}; p. pr. &
vb. n. {Tightening}.]
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.

{Tightening pulley} (Mach.), a pulley which rests, or is
forced, against a driving belt to tighten it.