slippery

adjective

• 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."

• (by extension) Evasive; difficult to pin down.

  "a slippery person"

• Liable to slip; not standing firm.
• Unstable; changeable; inconstant.
• Wanton; unchaste; loose in morals.