Complex sentence: A secret admirer is an individual who feels adoration, fondness or love for another person without disclosing his or her identity to that person, and who may send gifts or love letters to his or her crush.
Split into simpler sentences: A secret admirer is an individual who feels adoration, fondness or love for another person without disclosing his or her identity to that person. The admirer may often send gifts or love letters to his or her crush.