| sweet-toothed | | | |
| swell up | | | |
| swim with sharks | | | |
| swing back | | | |
| swing by | | | |
| swing of things | | | |
| swing through | | | |
| switch on | | | |
| sack drill | | | |
| saddle tramp | | | |
| safe in the knowledge | | | |
| salad | | | |
| salami slicing | | | |
| salt the earth | | | |
| same, same, but different | | | |
| save face | | | |
| save someone's face | | | |
| save the furniture | | | |
| say again | | | |
| say it all | | | |
| say the word | | | |
| scalding hot | | | |
| scare someone to death | | | |
| scare the living daylights out of | | | |
| school of hard knocks | | | |
| score off | | | |
| scrape the bottom of the barrel | | | |
| scratch beneath the surface | | | |
| scratch that | | | |
| scream bloody murder | | | |
| screen door on a submarine | | | |
| screw off | | | |
| scum of the earth | | | |
| sea legs | | | |
| second banana | | | |
| second nature | | | |
| secretary spread | | | |
| see daylight | | | |
| see into a millstone | | | |
| see someone's etchings | | | |
| see the forest for the trees | | | |
| see the wood for the trees | | | |
| see which way the cat jumps | | | |
| see you next Tuesday | | | |
| self-contained | | | |
| sell dearly | | | |
| sell ice to Eskimos | | | |
| sell one's body | | | |
| sellout | | | |
| send a message | | | |
| send shivers down someone's spine | | | |
| send to dorse | | | |
| separate the wheat from the chaff | | | |
| serve time | | | |
| set back | | | |
| set foot | | | |
| set in stone | | | |
| set one's cap at | | | |
| set one's watch back | | | |
| set store by | | | |
| set the record straight | | | |
| set the world on fire | | | |
| settle into | | | |
| settle with | | | |
| sew buttons | | | |
| sex talk | | | |
| sexual tension | | | |
| shadow of one's former self | | | |
| shake like a leaf | | | |
| shake the plum tree | | | |
| shanks' mare | | | |
| shape up or ship out | | | |
| sharp cookie | | | |
| shatter the ice | | | |
| shed blood | | | |
| she'll be right | | | |
| shifty-eyed | | | |
| shit-eating grin | | | |
| shit on toast | | | |
| shit sandwich | | | |
| shit the bed | | | |
| shoe-leather | | | |
| shoot from the lip | | | |
| shoot one's bolt | | | |
| shoot the breeze | | | |
| short fuse | | | |
| short on looks | | | |
| shot across the bow | | | |
| shot in the dark | | | |
| shove it up your ass | | | |
| show ankle | | | |
| shower thought | | | |
| show one's teeth | | | |
| show someone a thing or two | | | |
| show up | | | |
| shut my mouth | | | |
| shut one's gob | | | |
| sick as a parrot | | | |
| sick puppy | | | |
| sidesplitting | | | |