lovesickness

n.

相思病；痴情；

1. She has pined away since she got lovesickness.
   她自从得了相思病而益发憔悴。
2. As time went by, a lovesickness of fashionable clothes came into me.
   天长日久，我便害了一种迷恋时髦服装的相思病。

Lovesickness.
Lovesickness
Lovesickness:
Lovesickness in "Troilus"
A treatise on lovesickness:
Love, Lovesickness, and Melancholia
Curing lovesickness, with medicine?
Lovesickness and gender in early modern English literature
Lovesickness and Gender in Early Modern English Literature
In Pandora's Jar: Lovesickness in Early Greek Poetry
In Pandora's Jar: Lovesickness in Early Greek Poetry
Febris Erotica: Lovesickness in the Russian Literary Imagination
Book Review:Lovesickness in the Middle Ages: The "Viaticum"and Its Commentaries Mary Frances Wack