Adjective

(er)

Of a surface, having low friction, often due to being covered in a non-viscous liquid, and therefore hard to grip, hard to stand on without falling, etc.

Oily substances render things slippery .

(figuratively, by extension) Evasive; difficult to pin down.

a slippery person

a slippery promise

(obsolete) Liable to slip; not standing firm.

* 1602 , , III. iii. 84:

Which when they fall, as being slippery' standers, / The love that leaned on them, as ' slippery too, / Do one pluck down another, and together / Die in the fall.

unstable; changeable; inconstant

* Denham

The slippery state of kings.

(obsolete) wanton; unchaste; loose in morals

* 1610 , , I. ii. 273:

My wife is slippery ? If thou wilt confess –

Adjective

(en adjective)

(informal) Tending to slide or cause sliding; slippery.

* 1998 , Charles Rosen, Barney Polan's game: a novel of the 1951 college basketball scandals (page 58)

I always prefer playing indoors on a soft, bouncy, slidey wood surface because outdoor asphalt courts release the day's heat slowly and the softened tar sucks at the bottoms of your sneakers.

*{{quote-news, year=2007, date=July 15, author=Jon Pareles, title=Sounds Dire, Droll, Dreamy and on the Edge of Kitsch, work=New York Times citation

, passage=Tunes with titles like “Mazurka Maracaibo” shimmer with countless plucked strings. Mr. Brozman deploys everything from the small Bolivian charango to a Finnish harp called the kantele, while there’s usually something slidey to carry the melody. }}