- screen-fire
- scrimshank
- second
- sectoral
- secure
- section
- sector
- sectorial
- self-fier
- self-firer
- semaphore
- sentry
- sergeant
- sergeant-major
- serjeant
- serrefile
- service cap
- service dress
- service uniform
- serviceman
- shako
- shelter tent
- shew
- shewn
- shore-based
- shoulder-loop
- signal-gun
- silk
- shelter-trenches
- shoulder-strap
- shown
- shoulder
- show
- sick-call
- signal corps
- sir
- slope
- skip-bomb
- skirmish
- skirmisher
- sky-borne
- snafu
- sneezing gas
- snipe
- smoke-shell
- slit trench
- smoke-screen
- sortie
- slash
- smokeless powder
- smoker-screen
- sniper
- spade
- spot
- sprawl
- squad
- squadron
- spitfire
- stable
- stable-call
- staff
- standby
- stack
- staff sergeant
- stand
- sten
- staves
- stellenbosch
- storm
- storming
- storming-party
- stranglehold
- stood
- strength
- stretcher-party
- striker
- stripe
- sublieutenant
- submachine-gun
- subaltern
- substantive
- superfortress
- sutler
- sword
- table-money
- tactics
- tab
- tankhead
- tap
- task
- tattoo
- tankproof
- terrain
- terrier
- territorial
- thrust
- time-expired
- tin hat
- torpille
- trail