also: こいやみ
noun
Refers to the state of being lovesick; often used in literary or emotional contexts.
彼は恋病で何も手につかないようだ。
He seems unable to do anything because of lovesickness.
恋病にかかると、食欲がなくなることもある。
When you are lovesick, you may lose your appetite.
Synonym; 恋煩い is more common and slightly more literary.
Compound of 恋 (love) and 病 (illness). The reading こいやまい is standard; こいやみ is a less common variant.