Oh :) you were talking about that song. I also like it.These lines means the girl is like a poet's ghazal which gives him some moments of peace. You can try listening to some ghazal singers if you want ( i like jagjit Singh, nusrat fateh ali khan and ghulam ali).

No, ghazal is a form of poetry, generally about life, love and pain. It is considered very beautiful. There is a song in Hindi in which singer called his lover as shaayer ki ghazal meant she was beautiful ( I think you are talking about that song "  kisi shaayer ki ghazal, dream girl" , i am not sure)