S.
- Salmacian - One who wishes to have a mixed genital set
- Sex Assignment - The process by which one's biological sex is determined at birth.
- Spironolactone - A testosterone blocker often taken by trans-feminine individuals as a part of HRT.
- Stealth - When a transgender person lives and generally passes as their true gender without disclosing that they are trans.
- S.T.P. - Stand To Pee (device)