temperamental

Etymology

It is formed from English temperament + -al.^[2][3][4][5] Temperament is from Latin temperāmentum (“due mixture”), from temperō (“to mix in due proportion”), the source of temper.^[2][3]

Earliest recorded meaning

Of or relating to a person's temperament; constitutional: 1646, in Sir Thomas Browne's Pseudodoxia Epidemica;^[2][6][7] Etymonline dates it to the 1640s.^[3]

Semantic evolution

The adjective first belonged to the old physiology in which a person's temperament was the mixture of the bodily humours, and meant "constitutional".^[2][3] Johnson (1755) defined it so, quoting Browne.^[7] The modern sense, of a person given to erratic moods, is recorded from 1907, in the American Magazine,^[2][3] and it soon passed to things that behave unpredictably, such as machines.^[2][4][8]

Timeline

• 1646 – of or relating to temperament; constitutional.^[2][6]
• 1907 – of a person, moody, given to erratic moods; hence, of a thing, unpredictable.^[2][3]

Meanings

Adjective

1. Easily upset or irritated, with sudden changes of mood: a temperamental tenor.^[8][6]
2. Of, relating to or caused by temperament; constitutional.^[6][8][2]
3. (informal) Of a machine or thing, working erratically; unreliable: The temperamental old car would not start in the cold.^[8][4][6]

Word family

• temperamentally
• untemperamental

Related words

• temperament
• temper
• temperate
• temperature

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d e f Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
4. ^ a b c Shorter Oxford English Dictionary on Historical Principles (2002), 5th ed., ed. William R. Trumble and Angus Stevenson, Oxford: Oxford University Press
5. ^ Dictionary.com Unabridged (2016), based on the Random House Unabridged Dictionary, New York: Random House
6. ^ a b c d e Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
7. ^ a b Johnson, Samuel (1755), A Dictionary of the English Language, London; 4th ed. 1773; Johnson's Dictionary Online, ed. Beth Rapp Young et al.
8. ^ a b c d Collins English Dictionary (2023), Glasgow: HarperCollins