Vocabulary - The Humours of the Body

The ancient Greek medical practitioners believed that a healthy body had a balance of four humours (essential fluids) which gave an indication of someone’s temperament. An imbalance of humours was thought to cause a change in temperament.

Those humours were blood, bile (choler), black bile, and phlegm. Each humour was associated with a season and an element (air, water, fire, and earth). While we no longer use this theory to treat people these terms continue to be used in the English language.

Choleric:
Easily irritated or angered; hot-tempered.
Etymology:
From the Greek chole (bile).

Phlegmatic:
Having a sluggish temperament; apathetic.
Calm or composed.
Etymology:
From the Greek Phlegm which meant "inflammation, heat" (the humour phlegm was supposedly a result of heat)

Melancholic:
Gloomy; wistful.
Saddening.
Of or related to melancholia.
Etymology:
From the Greek melancholia (the condition of having an excess of black bile)

Bilious:
Extremely unpleasant.
Ill-natured; irritable.
Relating to bile.
Etymology:
From the Latin bilis (bile).

Sanguine:
Cheerfully optimistic or confident.
Having a healthy reddish color.
Blood-red.
Etymology:
From the Latin sanguis (blood).