enthusiasm

As an adjective keenest

is (keen).

As a noun enthusiasm is

(obsolete|or|historical) possession by a god; divine inspiration or frenzy.

As nouns the difference between heartiness and enthusiasm

is that heartiness is the characteristic of being hearty; fillingness; wholesomeness while enthusiasm is (obsolete|or|historical) possession by a god; divine inspiration or frenzy.

As nouns the difference between emotion and enthusiasm

is that emotion is a person's internal state of being and involuntary physiological response to an object or a situation, based on or tied to physical state and sensory data while enthusiasm is possession by a god; divine inspiration or frenzy.

As nouns the difference between enthusiasm and inspiration

is that enthusiasm is possession by a god; divine inspiration or frenzy while inspiration is the drawing of air into the lungs, accomplished in mammals by elevation of the chest walls and flattening of the diaphragm, as part of the act of respiration.

As nouns the difference between enthusiasm and exhilaration

is that enthusiasm is possession by a god; divine inspiration or frenzy while exhilaration is the act of enlivening the spirits; the act of making glad or cheerful; a gladdening.

As a noun enthusiasm is

(obsolete|or|historical) possession by a god; divine inspiration or frenzy.

Enthusiasm is a related term of feverishness.

As nouns the difference between enthusiasm and feverishness

is that enthusiasm is (obsolete|or|historical) possession by a god; divine inspiration or frenzy while feverishness is the quality of being feverish.

Enthusiasm is a related term of dash.

As nouns the difference between enthusiasm and dash

is that enthusiasm is (obsolete|or|historical) possession by a god; divine inspiration or frenzy while dash is (typography) any of the following symbols: (''horizontal bar ).

As a verb dash is

to run quickly or for a short distance.

As an interjection dash is

(euphemistic) damn!.

Radiance is a related term of enthusiasm.

As nouns the difference between radiance and enthusiasm

is that radiance is the quality of being radiant, shining, bright or splendid while enthusiasm is (obsolete|or|historical) possession by a god; divine inspiration or frenzy.

Pity is a related term of enthusiasm.

As nouns the difference between pity and enthusiasm

is that pity is (uncountable) a feeling of sympathy at the misfortune or suffering of someone or something while enthusiasm is (obsolete|or|historical) possession by a god; divine inspiration or frenzy.

As a verb pity

is to feel pity for (someone or something).

As an interjection pity

is short form of what a pity.