- streptococcus viridans
- streptolysin o
- sleepless person
- shaheed
- syphilitic
- Schistosoma
- snowcap
- shoulder mark
- suspensory
- suspensoid
- shin pad
- shoulder patch
- sundress
- shirtdress
- strapless
- starve out
- sound barrier
- sonic barrier
- shamash
- sealyham
- sleepy_eyed
- sleepyheaded
- sleepwalker
- somnambulation
- sleepy dick
- state emblem
- street virus
- surplice
- slip ring
- silver_tip
- sound spectrum
- spectrum shaping
- spectrum analyzer
- steamed
- shamefacedness
- shitlist
- sodium bichromate
- sodium dichromate
- second earl of chatham
- second degree nystagmus
- spectral characteristics
- spectral directional reflectance
- servo
- surgical intervention
- spanish gorse
- sir henry percy
- squamous cell
- spike suppressor
- stylistic
- steamfitter