Skittish

[William Hupy]

This comes to English from old Norse, but has its root in PIE. Am I wrong to use it to describe a reluctance to do something? Horses can be skittish, meaning very lively, apt to run.

[call_copse]

I think that's a fine (informal) usage, e.g. Theresa was a bit skittish when Donald suggested a trip to the lakeside - she remembered his tiny, wandering hands.