disc▪ According to Youssef2003, the word is from Eg st ‘woman’, but this is little likely.
▪ So perhaps short for sayyidaẗ (↗sayyid), via a st.const. form like sayyidaẗ-ī ‘my lady’ > *sīdaẗ-ī > *sīdẗ-ī > *sidẗ-ī > sitt-ī, without pron.suff. sitt ?
▪ Orel&Stolbova1994#2306: protSem *šitt‑ ‘lady’, protBerb *sut‑ ‘woman’, protWCh *sut‑ ‘sister’, CCh *sut‑ ‘girl’, all from AfrAs *süt‑ ‘woman’.