| SDt | standard deviation of total scores |
|---|---|
| SDU | standard deviation unit; step-down unit |
| SED | sedimentation rate; skin erythema dose; spondyloepiphyseal dysplasia; standard error of deviation; s... |
| s | Greek lower case letter sigma; conductivity; cross section; millisecond; molecular type or bond; pop... |
| UD | ulcerative dermatosis; ulnar deviation; undetermined; underdeveloped; unit dose; urethral dilatation... |