- symmetrically
- symmetry group
- symmetry
- saint elmo's fire
- saint ulmo's light
- saint elmo's light
- saint ulmo's fire
- sheela
- shinguard
- sound pressure
- solar wind
- solar prominence
- send_only service
- spammer
- surface chemistry
- sensibility
- sir thomas more
- seeded raisin
- seedless raisin
- singapore
- scarlet lychnis
- straggly
- sandiness
- smoothness
- spinmeister
- sleet
- splenic fever
- sea raven
- sea robin
- sea scallop
- sea route
- santiago ramon y cajal
- slip clutch
- sandbag
- subway
- subway fare
- sidetrack
- subzero
- standard erect position
- standard generalized markup language
- streamline flow
- steam line
- switch control computer
- spring frog
- soft chancre
- skin rash
- supression of urine
- surf fish
- surffusion
- surffish