SHOW A LOT OF HAIR to display courage ...1960s Amer. sl.
SIBILATE to hiss; to utter a hissing sound ...1656
SIBILATION the act of hissing or whistling; a hissing or whistling sound ...1626
SIBILLATORY marked or expressed by whistling ...1830
SICCATE to make dry ...1570 obs. rare
SICCATION the act or process of drying ...1612 obs.
SICKLIFY to make sick or sickly ...1851 rare
SIDE FOR SIDE alternately ...1519 obs.
SIDE-HANDED indirect ...1845
SIFT IN to arrive ...Bk1913-17 Amer. dial.
SINGLE-HEARTED straightforward, honest, sincere ...arch.
SINGLE-SOLED of a person: poor, mean, insignificant
SKATE a mean, dishonest person ...Bk1913-17 Amer. dial.
SKATE an old horse ...Bk1913-17 Amer. dial.
SKATE to hurry through something ...1960s Amer. sl.
SKINNY the latest information ...1960s Amer. sl.
SKIRT PATROL a search for female sexual partners ...1941 sl., orig. US
SKOOKUM strong, big ...Bk1913-17 Amer. dial.
SKWUZZY used as a term of approbation or compliment ...Bk1913-17 Amer. dial.
SLACKER THAN DISHWATER untidy, dirty, slovenly ...Bk1913-17 Amer. dial.
SLANG-WHANGER a careless talker ...Bk1913-17 Amer. dial.
SKRUTCH to crouch ...Bk1913-17 Amer. dial.
SLICK AS A GREASED PIG very pleasing, successful, pretty, etc.
...Bk1913-17 Amer. dial.
SLOOSH to rinse by throwing water upon ...Bk1913-17 Amer. dial.
SLOPEHEAD (derogatory or offensive) anyone from East Asia ...1966 US sl.
SLOWER THAN A JILL-POKE extremely slow ...Bk1913-17 Amer. dial.
SLUFFER one who fails to do his work ...Bk1913-17 Amer. college sl.
SLURB (derogatory) an area of unplanned suburban development ...M20 orig. US
SLUTCH mud, mire, slush ...M17 obs. exc. Eng. dial.
SLUTCHY muddy, slushy ...E18 obs. exc. Eng. dial.
SLYBOOTS a sly person, esp. one who does things on the sly ...colloq.
SMACKING of a breeze: blowing strongly or vigorously ...E19
SMACKING unusually large or fine ...L19 now colloq. & Eng. dial.