| 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... |
| SE | saline enema; sanitary engineering; side effect; smoke exposure; solid extract; sphenoethmoidal; spi... |
| SEM | sample evaluation method; scanning electron microscopy; secondary enrichment medium; standard error ... |