As for something unattainable

• A frenzy of emotion

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
"frenzy or rapture supposed to take hold of a man upon gazing on a nymph," 1775, coined by Richard Chandler, in "Travels in Greece," from nymph , on model of epilepsy , with second element from stem of Greek lambanein "to take." Especially "an ecstasy or ...

Wikipedia Word definitions in Wikipedia
Nympholepsy was the belief of the ancient Greeks that individuals could be possessed by the nymphs . Individuals who considered themselves nympholepts would display a great religious devotion to the nymphs. An example is Archedemos of Thera , who built ...

Wiktionary Word definitions in Wiktionary
n. A frenzied state of (usually erotic) emotion, especially concerning something or someone unattainable.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
Nympholepsy \Nym"pho*lep`sy\ (n[i^]m"f[-o]*l[e^]p`s[y^]), n. A species of demoniac enthusiasm or possession coming upon one who had accidentally looked upon a nymph; ecstasy. [R.] --De Quincey. The nympholepsy of some fond despair. --Byron.

WordNet Word definitions in WordNet
n. a frenzy of emotion; as for something unattainable