noun
being in love with an idol or actor; fan in love with a celebrity
Slang used in idol and fan communities. Can refer to the feeling itself or a fan who has romantic feelings for a celebrity. Often used in contrast to ガチ恋 (more serious) or リアコ (abbreviation).
あのアイドルにリア恋してるファンが多い。
There are many fans who are in love with that idol.
彼女は完全にリア恋で、推しのグッズを全部集めている。
She's totally a fan in love, collecting all of her favorite idol's merchandise.