unrequited
adjective formal or humorous uk/ˌʌn.rɪˈkwaɪ.tɪd/ us/ˌʌn.rɪˈkwaɪ.t̬ɪd/
（爱情）单方面的，得不到回报的，单相思的
If love that you feel for someone is unrequited, it is not felt in the same way by the other person.
It's just another poem on the pain of unrequited love. 这不过又是一首表现单相思之苦的诗。