Emily Dickinson Lexicon

PAR'OX-YSM, n. [Gr. παροξυσμος, from παροξυνω, to excite or sharpen; παρα, and οξυς, sharp.]

A fit of any disease. When a disease occurs by fits with perfect intermissions or suspensions, such fits are termed paroxysms. A paroxysm is always to be distinguished from an exacerbation.