sapient :: wise; shrewd
sardonic :: disdainful; sarcastic; cynical
saturnine :: gloomy
scrupulous :: conscientious; extremely thorough
scurrilous :: obscene; indecent
sebaceous :: oily; fatty
secular :: worldly; not pertaining to church matters; temporal
sedate :: composed; grave
sedentary :: requiring sitting
sedulous :: diligent
sensual :: devoted to the pleasures of the senses; carnal; voluptuous
sententious :: terse; concise; aphoristic
serrated :: having a saw-toothed edge
servile :: slavish; cringing
shoddy :: sham; not genuine; inferior
sidereal :: relating to the stars
simian :: monkeylike
sinister :: evil
sinuous :: winding; bending in and out; not morally honest
skittish :: lively; frisky
sleazy :: flimsy; unsubstantial
slovenly :: untidy; careless in work habits
solicitous :: worried; concerned
solvent :: able to pay all debts
somnolent :: half asleep
sonorous :: resonant
spasmodic :: fitful; periodic
spatial :: relating to space
specious :: seemingly reasonable but incorrect
spectral :: ghostly
splenetic :: spiteful; irritable; peevish
sporadic :: occurring irregularly
sportive :: playful
spurious :: false; counterfeit
squalid :: dirty; neglected; poor
stagnant :: motionless; stale; dull
staid :: sober; sedate
stellar :: pertaining to the stars
stentorian :: extremely loud
stolid :: dull; impassive
striated :: marked with parallel bands
strident :: loud and harsh
stringent :: binding; rigid
sublime :: exalted; noble; uplifting
sub rosa :: in strict confidence; privately
subsequent :: following; later
subservient :: behaving like a slave; servile; obsequious
subsidiary :: subordinate; secondary
subversive :: tending to overthrow or ruin
succinct :: brief; terse; compact
succulent :: juicy; full of richness
sultry :: sweltering
sumptuous :: lavish; rich
sundry :: various; several
superannuated :: retired on pension because of age
supercilious :: contemptuous; haughty
superficial :: trivial; shallow
supine :: lying on back
suppliant :: entreating; beseeching
supposititious :: assumed; counterfeit; hypothetical
surly :: rude; cross
surreptitious :: secret
sycophantic :: servilely flattering
sylvan :: pertaining to the woods; rustic
synchronous :: similarly timed; simultaneous with
synthetic :: artificial; resulting from synthesis
tacit :: understood; not put into words
taciturn :: habitually silent; talking little
tactile :: pertaining to the organs or sense of touch
tainted :: contaminated; corrupt
tautological :: needlessly repetitious
tawdry :: cheap and gaudy
temporal :: not lasting forever; limited by time; secular
tenacious :: holding fast
tentative :: provisional; experimental
tenuous :: thin; rare; slim
tepid :: lukewarm
terrestrial :: on the earth
terse :: concise; abrupt; pithy
tertiary :: third
testy :: irritable; short-tempered
therapeutic :: curative