Phonetic variant of Sadie, a pet form of Sarah meaning 'princess' in Hebrew.
Saidee is an elaborated spelling variant of Sadie, which itself began as a pet form of Sarah — the Hebrew שָׂרָה, meaning princess or noblewoman. Sarah is one of the oldest women's names in recorded Western use, borne by Abraham's wife in Genesis, the mother of Isaac and one of the matriarchs of the Jewish, Christian, and Islamic traditions. The transformation from Sarah to Sadie to Saidee traces the long, affectionate journey of a name through centuries of colloquial use, each iteration a small act of creative domestication.
Sadie emerged as an independent given name in the nineteenth century, particularly popular in England and America where the fashion for informal, affectionate names ran strong — the same era that gave us Nellie, Mamie, and Bessie as standalone names. By the early twentieth century, Sadie had a lively, slightly roguish quality, associated with music-hall songs and working-class vitality. G.
Wodehouse gave the world 'Bill,' and the popular song 'Sadie Salome' brought the name a comic theatrical energy it has never quite shed. Saidee, with its distinctive double-e ending, transforms that energy into something more decorative and personal. The spelling slows the name down slightly, makes it look at itself in the mirror.
It belongs to a tradition of nineteenth and early twentieth century American spelling variations that treated the written form of a name as a canvas for personality. Today it has the quality of a found name — something unearthed in an old family Bible or a cemetery record, brought back into use by someone who recognized its particular beauty.