Tenterhooks

Tenterhooks: Tenterhooks were used (centuries ago) to attached woolen cloth to a tenter (stretching frame) to prevent it from shrinking. The tenter shares its etymology with tension. For the last couple of centuries, wool manufacturing has been automated and on tenterhooks is only used metaphorically to refer to someone who is tense or anxious.

I'm on tenterhooks! Come on, Thomas, what's the great news then?