| sREM | stage rapid eye movement |
|---|---|
| SSCF | sleep stage change frequency |
| SSEA | stage-specific embryonic antigen |
| St, st | let it stand [Lat. stet]; let them stand [Lat. stent]; stage [of disease]; status; stere; sterile; s... |
| A2 | Aortic Component of the Second Heart Sound(S2) |