means An excessive, often irrational enthusiasm or compulsion for something, or a clinical state of abnormally elevated mood and frenzied energy.

from Straight from the Greek 'mania,' meaning madness or frenzy — itself rooted in the verb 'mainesthai,' to rage or be furious. The Greeks linked it to a whole family of words about the mind and its undoing, possibly a cousin of 'menos' (spirit, force) and even distantly of 'mind' itself. It passed through Latin into the medical and literary languages of Europe, where it kept its double life: a diagnosis on one side, and on the other a suffix of obsession — bibliomania, tulipmania — naming every crowd that ever lost its head over a single shining thing.