Adjective

(er)

Thin; slim.

*{{quote-book, year=1963, author=(Margery Allingham)

, title=(The China Governess) , chapter=3 citation , passage=Sepia Delft tiles surrounded the fireplace, their crudely drawn Biblical scenes in faded cyclamen blending with the pinkish pine, while above them, instead of a mantelshelf, there was an archway high enough to form a balcony with slender balusters and a tapestry-hung wall behind.}}

(Gaelic languages)  Palatalized.

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 –