Quick vs. Keen — What's the Difference?

Moving fast or doing something in a short time

Having or showing eagerness or enthusiasm

Prompt to understand, think, or learn; intelligent

(of a sense) highly developed

At a fast rate; quickly

(of the edge or point of a blade) sharp

The soft tender flesh below the growing part of a fingernail or toenail.

(of activity or feeling) intense

Those who are living

Excellent

A fast bowler.

Wail in grief for a dead person

Moving or functioning rapidly and energetically; speedy

An Irish funeral song accompanied by wailing in lamentation for the dead.

Learning, thinking, or understanding with speed and dexterity; bright

Having a fine, sharp cutting edge or point.

Perceiving or responding with speed and sensitivity; keen

Having or marked by intellectual quickness and acuity.

Reacting immediately and sharply

Acutely sensitive

Occurring, achieved, or acquired in a relatively brief period of time

Sharp; vivid; strong

Done or occurring immediately

Intense or bracing

Moving with speed, rapidity or swiftness, or capable of doing so; rapid; fast.

Pungent; acrid

Occurring in a short time; happening or done rapidly.

Ardent; enthusiastic

Lively, fast-thinking, witty, intelligent.

Eagerly desirous

Mentally agile, alert, perceptive.

(Slang) Great; splendid; fine

Of temper: easily aroused to anger; quick-tempered.

A loud wailing or lament for the dead.

(archaic) Alive, living.

To wail in lamentation, especially for the dead.

Pregnant, especially at the stage where the foetus's movements can be felt; figuratively, alive with some emotion or feeling.

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

Of water: flowing.

Fierce, intense, vehement.

Burning, flammable, fiery.

Having a fine edge or point; sharp.

Fresh; bracing; sharp; keen.

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

Productive; not "dead" or barren

Acrimonious, bitter, piercing.

Quickly, in a quick manner.

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

Answer quickly.

(Britain) Of prices, extremely low as to be competitive.

Raw or sensitive flesh, especially that underneath finger and toe nails.

Marvelous.

Plants used in making a quickset hedge

(obsolete) Brave, courageous; audacious, bold.

The life; the mortal point; a vital part; a part susceptible to serious injury or keen feeling.

To make cold, to sharpen.

Quitchgrass.

(transitive) To utter with a loud wailing voice or wordless cry.

(cricket) A fast bowler.

(transitive) To mourn.

(transitive) To amalgamate surfaces prior to gilding or silvering by dipping them into a solution of mercury in nitric acid.

A prolonged wail for a deceased person.

To quicken.

Sharp; having a fine edge or point; as, a keen razor, or a razor with a keen edge.

Alive; living; animate; - opposed to dead or inanimate.

Acute of mind; sharp; penetrating; having or expressing mental acuteness; as, a man of keen understanding; a keen look; keen features.

Characterized by life or liveliness; animated; sprightly; agile; brisk; ready.

Bitter; piercing; acrimonious; cutting; stinging; severe; as, keen satire or sarcasm.

Speedy; hasty; swift; not slow; as, be quick.

Piercing; penetrating; cutting; sharp; - applied to cold, wind, etc.; as, a keen wind; the cold is very keen.

Impatient; passionate; hasty; eager; eager; sharp; unceremonious; as, a quick temper.

Eager; vehement; fierce; as, a keen appetite.

Fresh; bracing; sharp; keen.

Wonderful; delightful; marvelous; as, that would be keen.

Sensitive; perceptive in a high degree; ready; as, a quick ear.

To sharpen; to make cold.

Pregnant; with child.

To wail as a keener does.

In a quick manner; quickly; promptly; rapidly; with haste; speedily; without delay; as, run quick; get back quick.

A prolonged wail for a deceased person. Cf. Coranach.

That which is quick, or alive; a living animal or plant; especially, the hawthorn, or other plants used in making a living hedge.

A funeral lament sung with loud wailing

The life; the mortal point; a vital part; a part susceptible of serious injury or keen feeling; the sensitive living flesh; the part of a finger or toe to which the nail is attached; the tender emotions; as, to cut a finger nail to the quick; to thrust a sword to the quick, to taunt one to the quick; - used figuratively.

Express grief verbally;

Quitch grass.

Having or demonstrating ability to recognize or draw fine distinctions;

To revive; to quicken; to be or become alive.

Intense or sharp;

Any area of the body that is highly sensitive to pain (as the flesh underneath the skin or a fingernail or toenail)

Very penetrating and clear and sharp in operation;

Accomplished rapidly and without delay;

Very good;

Hurried and brief;

As physically painful as if caused by a sharp instrument;

Moving quickly and lightly;

Having a sharp cutting edge or point;

Apprehending and responding with speed and sensitivity;

Performed with little or no delay;

Easily aroused or excited;

With little or no delay;