Tenterhooks not tender hooks.

[Seymour5]

Tenterhooks were used in weaving, in relation to the tension of stretched fabric. It became a term used to signify nervousness. ‘She was on tenterhooks waiting for her results’.

I only recently found this out, OP.

I thought it was "tender hooks". I thought "tender hooks" was the name of the hooks that went through fish mouths/cheeks when they're hung from the ceiling to dry. I thought they were tender hooks because they were a special kind of hook that kept the fish meat tender.

I think I completely invented every single element of that scenario during childhood and it just kind of stuck.

I transcribe old Parish records for a genealogy website and Tenter used to be an occupation in mills.

MN is full of mentions of tenderhooks.

Went to Hogarth exhibition at Tate Britain a few years ago. Old maps show large areas marked Tenter grounds or fields. Particularly noticed them west of London Bridge.
Quick google gave
“There are several marked 'tenter grounds' on the map: fields or areas of open ground where washed new cloth was stretched out on tenter hooks to dry.”

Exactly so. And as @JudgeJ says, ‘tenter’ was an occupation.

This is really sweet!

I used to love in an area called the Tenters, because of this origin

Live in. Though I did also love in the area