Definition & Meaning of "on tenterhooks"

What is the origin of the idiom "on tenterhooks" and when to use it?

The origin of the idiom "on tenterhooks" can be traced back to the textile industry in the 15th century. A tenter was a wooden frame with hooks or nails on which cloth was stretched during the process of drying or finishing. The hooks, called "tenterhooks," were used to hold the fabric tightly in place. The phrase can be used in personal situations, such as awaiting exam results, job interviews, or medical test results, where there is a high level of nervousness or anticipation.