Sidechick Syn·dro·me 1. A female who is use to being second or at a lower position in her partner(s) heart. 2. One who feels she is not worthy of love to the fullest potential. "Man my jump-off is crazy! I think she got sidechick syndrome." Synonyms: Low morals, secret texting/calling, excessive crying, dreaming at night of being number one, memory loss of their position, delusion... No medicine can cure this sickness...