Sabre-rattling

Sacred cow

Safe and sound

Safe as houses

Safe bet

Safe pair of hands

Safety in numbers

Saigon moment

Sail close to the wind

Sail under false colours

Salad days

Salt in a wound

Salt of the earth

Salty dog

Same old, same old

Save face

Save someone’s bacon

Save your skin

Saved by the bell

Saving grace

Say uncle

Say when

Say-so

Saying is one thing; doing is another

Scales fall from your eyes

Scarce as hen’s teeth

Scare the daylights out of someone

Scarlet woman

Scattered to the four winds

Scent blood

Schoolyard pick

Scot free

Scotch Mist

Scraping the barrel

Scratch the surface

Scream bloody murder

Scream blue murder

Screw loose

Screwed if you do, screwed if you don’t

Sea change

Sea legs

Seamy side

Searching question

Second thoughts

Second wind

Second-guess

See eye to eye

See red

See the elephant

See the light

See which way the cat jumps

See you anon

See you later

See you on the big drum

Seed money

Seeing is believing

Seen better days

Sell down the river

Sell like hot cakes

Sell like hotcakes

Sell your birthright for a mess of pottage

Sell your soul

Send someone packing

Send someone to Coventry

Senior moment

Separate the sheep from the goats

Separate the wheat from the chaff

Serve time

Serve your country

Set a thief to catch a thief

Set in stone

Set the stage

Set the Thames on fire

Set the wheels in motion

Set your sights on

Set your teeth on edge

Settled on your lees

Seven sheets to the wind

Seventh heaven

Shades of meaning

Shaggy dog story

Shake a leg

Shanks’s pony

Shape up or ship out

Sharks are circling

Sharp as a tack

Sharp cookie

Sharpen your pencil

She’ll be apples

Shed light

Shifting sands

Shilly-shally

Ship came in

Shipshape and Bristol fashion

Shoe is on the other foot

Shoestring

Shoot down in flames

Shoot from the hip

Shoot the breeze

Shoot your wad

Shoot yourself in the foot

Shooting fish in a barrel

Shop floor

Short end of the stick

Short horse soon curried

Short shrift

Short-change

Shot across the bow

Shot in the dark

Shotgun marriage

Show me the money

Show someone a clean pair of heels

Show someone the ropes

Show your true colors

Shrinking violet

Shy bairns get nowt

Sick and tired

Sick as a dog

Sick as a parrot

Sick to death

Sight for sore eyes

Sight to behold

Signed, sealed and delivered

Silence is golden

Silly season

Silver bullet

Silver screen

Silver surfer

Since time immemorial

Sing for your supper

Sing from the same hymn sheet

Sing like a canary

Sing the blues

Sink or swim

Sit on the fence

Sit pretty

Sit well with

Sitting duck

Six feet under

Six of one and half-a-dozen of the other

Sixes and sevens

Sixty-four-thousand-dollar-question

Skate on thin ice

Skeleton in the closet

Skin and bones

Skin in the game

Skin someone alive

Skunkworks

Sky is the limit

Slap leather

Slap on the wrist

Slave driver

Sleep like a baby

Sleep like a log

Sleep well- don’t let the bedbugs bite

Sleight of hand

Slim chance

Sling your hook

Slip of the tongue

Slip through one’s fingers

Slip through the cracks

Slip through the net

Slippery customer

Slippery slope

Slough of despond

Slow and steady wins the race

Slow boat to China

Slow but sure

Slow off the mark

Slower than molasses going uphill in January

Slowly, slowly catchy monkey

Sly as a fox

Smack in the face

Small beer

Small dog, tall weeds

Small fry

Small potatoes

Small-time

Smart Alec

Smart as a whip

Smarty pants

Smell a rat

Smoke and mirrors

Smoke like a chimney

Smoke the peace pipe

Smokestack industry

Smoking gun

Smooth as a baby’s bottom

Smooth sailing

Snake in the grass

Snake oil

Snake oil salesperson

Snipe hunt

Snug as a bug in a rug

So it goes

So on and so forth

So what

Sod’s law

Soft shoe

Soft soap someone

Some other time

Something nasty in the woodshed

Sound as a bell

Sound as a pound

Sour grapes

Sow the seeds

Sow your wild oats

Spanish practices

Spanner in the works

Spare the rod and spoil the child

Speak of the devil!

Speak softly and carry a big stick

Speak to the organ grinder not the monkey

Speak volumes

Speak with a forked tongue

Speak your mind

Spend a penny

Spend like a sailor

Spice of life

Spick and span

Spike your guns

Spill the beans

Spin a yarn

Spinning a line

Spinning a yarn

Spirit is willing, but the flesh is weak

Spirit of the law

Spit blood

Spit it out

Spit nails

Spit the dummy

Spitting image

Split hairs

Split the blanket

Spoil the ship for a ha’pworth of tar

Spoilt for choice

Spot on

Sprat to catch a mackerel

Spread the word

Spread yourself too thin

Spring chicken

Spring to mind

Spur of the moment

Sputnik moment

Square meal

Square Mile

Square peg in a round hole

Square the circle

Squared away

Squeaky clean

Squeaky wheel gets the grease

Squeeze blood out of a turnip

Stake a claim

Stalking horse

Stand head and shoulders above

Stand in good stead

Stand tall

Stand the test of time

Stare down the barrel of a gun

Stars and stripes

Stars in your eyes

Start from scratch

State of the art

Status quo

Stay the course

Steal a march

Steal someone’s thunder

Steal the show

Steer clear of

Stem the tide

Step on it

Step on someone’s toes

Step up a gear

Step up to the plate

Stew in your own juices

Stick in your craw

Stick out like a sore thumb

Stick to your guns

Stick your neck out

Stick-in-the-mud

Sticking point

Sticks and stones may break my bones, but names will never hurt me

Sticky end

Sticky fingers

Sticky wicket

Stiff as a poker

Stiff upper lip

Stiff-necked

Still in the game

Still waters run deep

Stir the blood

Stir the pot

Stitch in time saves nine

Stone dead

Stone deaf

Stone the crows

Stone’s throw

Stool pigeon

Stop a clock

Stop cold

Stop on a dime

Stop the music

Storm in a teacup

Straddle the fence

Straight and narrow

Straight as an arrow

Straight face

Straight from the shoulder

Straight red

Strain every nerve

Strange at the best of times

Strapped for cash

Straw man

Straw poll

Straw that broke the camel’s back

Streets ahead

Strike a chord

Strike while the iron is hot

Stroke of luck

Stroll down memory lane

Strong as an ox

Stubborn as a mule

Stuffed shirt

Stuffed to the gills

Succeed in the clutch

Suck hind teat

Sunday driver

Sure as eggs is eggs

Sure-fire

Swan song

Swear like a sailor

Swear like a trooper

Sweat blood

Sweat bullets

Sweat like a pig

Sweep off your feet

Sweep things under the carpet

Sweet as a gumdrop

Sweet tooth

Sweet-talk

Sweeten the pot

Swim against the tide

Swim with the fishes

Swim with the tide

Swimmingly

Swing into action

Swing the lead

Swinging door

Swings and roundabouts