The phrase "a cliff of a" is correct and usable in written English.
It is typically used to emphasize the significance or dramatic nature of something, often in a metaphorical sense.
Example: "That was a cliff of a decision to make, and it changed the course of our project."
Alternatives: "a monumental" or "a significant".
Emboldened, they walk the streets, bearing the possibility that we, as a nation, may be stepping off a cliff of denial into a valley of hatred, fear and fascism.
When the giant B. Altman closed on 34th and Fifth in 1989, it left Lord & Taylor on a cliff of retail geography, like a large beachfront house where erosion now approaches the front porch.
Aso-S rupture band extends along the Nigori-gawa River, which has a straight gully with a cliff of north side down topography indicating an active fault.
Before creating Robi, Takahashi built a small robot that climbed a cliff of the Grand Canyon.
I'm staring over the edge of a cliff into a seam of coal some 80 feet thick running along a chasm cut deep into the earth.
"As far as I'm concerned, British food went downhill after the 1950s, was still good in the 1970s and has since fallen off the edge of a cliff into a sea of mass suppliers, arrogance and absurdity".
As it happened, she was just in time to watch her country's slo-mo dive off the edge of a cliff in a fit of plutocratic triumphalism.
The Dâyet et-Tefla pool (19°43'121 N, 12°52'012 W) is located at the foot of a cliff in a meander of the Nbéïké wadi.
If you're looking to eat a snack that will help you train, try a banana, a peach, half of a Cliff bar, a piece of wheat toast, or an English muffin with jelly.
The port, commercial district, and adjoining residential zones lie at the foot of a cliff on a low shelf of land facing west onto the bay, only a few feet above sea level.
