ETYMOLOGY
from down (in a descending direction) + steepy (full of steep places, steep)
EXAMPLE
“… All which notwithstanding, perceiving life to remaine in him, he tooke heart againe; and getting vp on his feet, all goared with bloud, and loaden with strokes, making way through the prease, came to a craggie and downe-steepie rocke, where vnable to goe any further, by one of his wounds, with both his hands he pulled out his guts, and tearing and breaking them, cast them amongst such as pursued him, calling and attesting the vengeance of God to light vpon them. …”
From: The Essayes, or Morall, Politike, and Millitarie Discourses of Lord Michaell de Montaigne
By Michel de Montaigne
Translated by John Florio, 1603
Lexicophilia 