Exasperation, n.
Etymology: [L. exasperatio: cf. F. exaspération.]
1. The act of exasperating or the state of being exasperated; irritation; keen or bitter anger. Extorted from him by the exasperation of his spirits. South.
2. Increase of violence or malignity; aggravation; exacerbation. "Exasperation of the fits." Sir H. Wotton.
Shades of meaning
Fernald has no entry of its own for exasperation; he lists it under anger.
Where he writes about it:
Exasperation, a roughening, is a hot, superficial intensity of anger, demanding instant expression. — from anger