Turnbuckle
WordNet
noun
(1) An oblong metal coupling with a swivel at one end and an internal thread at the other into which a threaded rod can be screwed in order to form a unit that can be adjusted for length or tension
WiktionaryText
Noun
- A coupling device consisting of two eyelets or other connection points connected in screw threads. The joint in between can be turned to shorten or lengthen the device with mechanical advantage provided by the screw threads.
- A link threaded on both ends of a short bar which is used to pull objects together. (FM 55-501)