- Siphon
- Sipoy
- Sipping
- Sire
- Sister
- Sister-in-law
- Sisterhood
- Sisterly
- Sit
- Sit by
- Sit down
- Sit on
- Sit out
- Sit through
- Sit up
- Sita
- Sitting near
- Sitting target
- Sitting tenant
- Situated
- Situations vacant
- Siveringly
- Six feet under
- Six-shooter
- Sixth sense
- Sixties
- Sixtieth
- Sixty-nine
- Skanky
- Skater
- Skating
- Skeleton in the closet
- Skeleton key
- Skeptic
- Skeptical
- Skilful
- Skilful physician
- Skill-less
- Skilless
- Skillfulness
- Skillion
- Skim away
- Skimp
- Skin game
- Skin tag
- Skin tight
- Skin-deep
- Skinflint
- Skint
- Skip
- Skippers daughters
- Skirling
- Skittishly
- Skive
- Skiver
- Skulker
- Skulking place
- Skulless
- Skunk
- Sky wave
- Sky-blue
- Skylark
- Skylight
- Skyline
- Skyscraper
- Slab-sided
- Slabby
- Slack off
- Slack up
- Slacks
- Slaggy
- Slalom
- Slanderer
- Slanderous
- Slang
- Slangingly
- Slangs
- Slantwise
- Slap on the back
- Slapped
- Slapper
- Slapping
- Slapstick
- Slasher
- Slate-blue
- Slaughtered
- Slave labour
- Slavic
- Slavish
- Sleekness
- Sleep apnea
- Sleeping
- Sleeping by turns
- Sleeping policeman
- Sleepless
- Sleet
- Sleetiness
- Slitter
- Sleeved
- Sleight