A fork of Rural Dictionary
An affectionate female nickname derived from the word sister. Sissy is a common nickname for a female sibling. It can also be a nickname given to a girl by others that she has cared for or behaved sisterly towards. The nickname implies that the girl is a sister or is regarded as such by family and friends. All in all, a sweet, caring girl :-) See sister, sis, girl, female
Little Sis: I love you, Sissy. Sissy: Awww, I love you too.