- spotting
- spring force
- spring hanger
- springy force
- Stark effect
- starlight
- starting friction
- state quantity
- static head
- static resistance
- static thrust
- statical force
- stationary phase
- statistical thermodynamics
- squealing
- squid
- stability diagram
- stabilization process
- stable equilibrium
- stable isotope
- stage
- stand
- steady current
- steady motion
- steady noise
- steering system
- Steinmetz law
- statoscope
- steel locker
- steel tendon
- steering
- stereo viewer
- stereoscope
- stereoscopy
- stochastic loading
- stokes" law
- stop bath
- stop motion
- stop plate
- stoppered flask
- storage
- storage cupboard
- stereoscopic camera
- sticking voltage
- stoppered bottle
- stopping potential
- storage ring
- still camera
- stokes" theory
- stop
- stop down
- stop pin
- storage canister
- storage period
- straight negative
- strainer
- strangeness
- strapping
- stigmatic lens
- stopped lens
- stray capacitance
- stray oscillation
- stray radiation
- streak lines
- stream function
- streamline pattern
- stretcher
- stretcher ring
- strike note
- string construction
- studio
- sump
- sunk mount
- superconducting
- superconductor
- supercooled
- superlattice nanowire
- superluminessence
- strip
- strouhal number
- stylus force
- subatomic particle
- subcool
- subdominant
- submediant
- sulfide toning
- studio work
- study room
- subcritical reaction
- strong
- subjective tone
- subshell
- sunk setting
- super-refraction
- superconductivity
- supernova neutrino
- supersonic speed
- supersymmetrical particles
- supertonic
- supertrings