| stand up and be counted |
| star-crossed |
| stars are aligned |
| start over |
| start with a clean slate |
| state of affairs |
| stay behind |
| stay on |
| steady-as-she-goes |
| steal a march |
| steal the show |
| steely-spined |
| step down |
| step lively |
| step on it |
| step out |
| stepping razor |
| step up |
| step up to the plate |
| stick a fork in something |
| sticker shock |
| sticking-place |
| sticking point |
| stick in the mud |
| stick it to the man |
| stick one's foot in it |
| stick one's head in the sand |
| stick one's nose into |
| sabre-rattling |
| sacked out |
| sacred cow |
| sad drunk |
| safe and sound |
| sail the high seas |
| sail under false colors |
| salad days |
| salami-slice |
| salt away |
| salt of the earth |
| salty tooth |
| same old story |
| Santa's workshop |
| saved by the bell |
| save for a rainy day |
| save one's breath |
| save someone's life |
| save the day |
| sawdust trail |
| saw wood |
| say cheese |
| say grace |
| say no more |
| say the quiet part loud |
| say uncle |
| say when |
| scared green |
| scared to death |
| scare story |
| scare the life out of |
| scare the pants off |
| schoolboy error |
| Schrödinger's douchebag |
| scope out |
| Scotch mist |
| scrape someone off the ceiling |
| scrape through |
| scratch an itch |
| scratch by |
| scratch one's own itch |
| scratch the itch |
| scratch together |
| screaming trots |
| scream one's head off |
| screwed, blued and tattooed |
| screw it |
| screw the pooch |
| screw you |
| sea change |
| seagull manager |
| sea load |
| seat-of-the-pants |
| second childhood |
| second gear |
| second-rate |
| second Tuesday of the week |
| see a man |
| see a man about a horse |
| see eye to eye |
| seeing is believing |
| see one's way clear to |
| see red |
| see something green in one's eye |
| see the dark side of the moon |
| see the light |
| see the trees through the forest |
| see things |
| see what sticks |
| see with half an eye |
| see you later |
| seismic shift |