deep vs keen

Hard to penetrate or comprehend; profound; intricate; obscure. 

In a (specified) number of rows or layers. 

Positioned or reaching far, especially down through something or into something. 

Voluminous. 

Far in extent in another (non-downwards, but generally also non-upwards) direction away from a point of reference. 

Low in pitch. 

Far from the center of the playing area, near to the boundary of the playing area, either in absolute terms or relative to a point of reference. 

Distant in the past, ancient. 

Significant, not superficial, in extent. 

Muddy; boggy; sandy; said of roads. 

Extending far down from the top, or surface, to the bottom, literally or figuratively. 

Penetrating a long way, especially a long way forward. 

Positioned back, or downfield, towards one's own goal, or towards or behind one's baseline or similar reference point. 

Thick. 

Profound, having great meaning or import, but possibly obscure or not obvious. 

Extending to a level or length equivalent to the stated thing. 

Highly saturated; rich. 

Sound, heavy (describing a state of sleep from which one is not easily awoken). 

Of penetrating or far-reaching intellect; not superficial; thoroughly skilled; sagacious; cunning. 

In a profound, not superficial, manner. 

In large volume. 

Back towards one's own goal, baseline, or similar. 

Far, especially far down through something or into something, physically or figuratively. 

Acute of mind, having or expressing mental acuteness; penetrating, sharp. 

Often with a prepositional phrase, or with to and an infinitive: showing a quick and ardent responsiveness or willingness; eager, enthusiastic, interested. 

Having a fine edge or point; sharp. 

Of cold, wind, etc.: cutting, penetrating, piercing, sharp. 

Of prices, extremely low as to be competitive. 

Acrimonious, bitter, piercing. 

Fierce, intense, vehement. 

To utter with a loud wailing voice or wordless cry. 

To mourn. 

To make cold, to sharpen. 

To utter a keen.