This song is about being an independent women; and discusses the many situations women find themselves when they don’t want male attention. The song is sending a message that it is okay to know what you want and acknowledging you don’t have to give your attention to people you don’t know or like. A scrub refers to a male that is undesirable for many reasons mentioned throughout the song. The song has become an anthem for women which highlights the expectation that women should accept whatever male attention they receive.
Link to Lyrics: https://genius.com/Tlc-no-scrubs-lyrics