[turn-buhk-uh
l] 
| a link or sleeve with a swivel at one end and an internal screw thread at the other, or with an internal screw thread at each end, used as a means of uniting or coupling, and of tightening, two parts, as the ends of two rods. |
| turn·buck·le (tûrn'bŭk'əl) n. A metal coupling device consisting of an oblong piece internally threaded at both ends into which the corresponding sections of two threaded rods are screwed in order to form a unit that can be adjusted for tension or length. |