S

1. Abbreviation for sacral vertebra (S1–S5); spherical, spherical lens; Svedberg unit. 2. Symbol for siemens; sulfur; entropy in thermodynamics; substrate in the Michaelis-Menton mechanism; percentage saturation of hemoglobin (when followed by subscript O₂ or CO); serine; one of the two stereochemical designations (in italics) in the Cahn-Ingold-Prelog system. 3. Designation of a rare human antigen (hemagglutinogen) related genetically to the MNSs blood group. See Blood Groups appendix.

Symbol for entropy.

* * *

apparent power; in electrocardiography, a negative deflection that follows an R wave [wave]; entropy; exposure time; half [Lat. semis]; left [Lat. sinister]; mean dose per unit cumulated activity; the midpoint of the sella turcica [point]; sacral; saline; Salmonella; saturated; scanning [pacemaker]; Schistosoma; schizophrenia; scleral [tumor invasion]; second; section; sedimentation coefficient; sella [turcica]; semilente [insulin]; senile, senility; sensation; sensitivity; septum; serine; serum; serum marker; Shigella; siderocyte; siemens; sigmoid; signature [prescription]; silicate; slope; single; slow accelerator; small; smooth [colony]; soft [diet]; solid; soluble; solute; sone [unit]; space; spatial; specificity; spherical; Spirillum; spleen; spontaneous; standard normal deviation; Staphylococcus; stem [cell]; stimulus; Streptococcus; streptomycin; subject; subjective findings; substrate; sulfur; sum of an arithmetic series; supravergence; surface; surgery; suture; Svedberg [unit]; swine; Swiss [mouse]; synthesis; systole; without [Lat. sine]

* * *

S abbr

1) sacral used esp. with a number from 1 to 5 to indicate a vertebra or segment of the spinal cord in the sacral region <the relative length of cord segments S1 to S5>

2) signa used to introduce the signature in writing a prescription

3) smooth used of bacterial colonies

4) subject

5) svedberg

S symbol sulfur

* * *

spherical lens; serine; siemens; smooth (see under colony); substrate; sulfur; Svedberg unit; sacral vertebrae (S1 through S5).