As adjectives the difference between cliffy and steep
is that
cliffy is abounding in cliffs while
steep is of a near-vertical gradient; of a slope, surface, curve, etc that proceeds upward at an angle near vertical.
As a verb steep is
(ambitransitive) to soak an item (or to be soaked) in liquid in order to gradually add or remove components to or from the item.
As a noun steep is
a liquid used in a steeping process.