- sheath
- sheathe
- shelf coil
- shelf froster
- shell correction
- shell ice
- shell insulation
- shielded pair
- shielding
- shielding ratio
- shifting operator
- ship station
- shock absorbing
- shock resistance
- shore effect
- short-focus
- short-range
- shortwave satellite
- shot noise
- shrinkable film
- shrinkage value
- shunt
- shunt generator
- shunt motor
- shunt reactor
- shunt regulator
- side
- side frequency
- sideband
- sidereal house
- sidereal time
- sidetone
- sight glass
- signal selector
- signal transducer
- signal winding
- signalling key
- signalling point
- signless
- silent
- silent discharge
- silent zone
- silica
- similitude relations
- Simon liquefier
- simple electrode
- simple liquid
- simple tone
- simplex channel
- simplex winding
- simplified
- simulated conditions
- simulation chamber
- sine condition
- sine wave
- single bus
- single lens
- single potential
- share
- sharing
- sharp series
- shear strain
- sheet grating
- sheet insulation
- sheet steel
- shelf battery
- shelf freezer
- shelf life
- shelf test
- shell freezing
- sheltered installation
- Sherwood number
- shock breaking
- shock current
- shock excitation
- shock front
- shock strength
- shock stress
- short-lived
- shorten
- shortening
- shortwave band
- shortwave radiation
- shortwavelength approximation
- shot effect
- shrink
- shrinkage
- shrinkage gradient
- shunt loading
- shunt transition
- shunt-wound
- shuttle
- SI units
- shortwave diathermy
- shunt capacitor
- shunt trip
- shunt-excited
- shunting
- shut-down
- shutoff device