aberration

Etymology

It is borrowed from Latin aberrātiō (“diversion, relief”),^{[2][3][4][5][6]} which in post-classical Latin also meant an error or mistake.^[2] The noun comes from aberrō (“to wander away, go astray”),^[2][3][5][6] from ab- (“away from”) and errō (“to wander, stray”),^[3][5][6] whose root Proto-Indo-European *ers- is given by the American Heritage Dictionary.^[3] The astronomical sense follows French aberration, used in astronomy from 1733 and recorded as "straying" from 1624.^[2] It is related to aberrant and err.^[7][6]

Earliest recorded meaning

A departure from what is normal or expected: 1588, in R. Some's defence of his treatise on the ministry.^[2][4] Barnhart gives 1594,^[6] and Etymonline the 1590s, with the meaning "a wandering, act of straying".^[5]

Semantic evolution

The word has been both literal and figurative since the 16th century: the literal straying from a course is recorded from before 1594 to 1830,^[2] and the departure from a moral standard from 1594.^[2] Johnson (1755) defined it as "the act of deviating from the common track".^[8] H. Crooke's Mikrokosmographia of 1615 is the first record of two narrower senses, a passing impairment of reason, now chiefly in mental aberration, and a deviation from a natural type,^[2] which Etymonline dates only to 1735.^[5] Science then gave the word two technical meanings: in optics, from a letter of Newton's of 1672, the failure of rays of light to meet at one focus,^[2] and in astronomy, from 1737, the apparent shift of a celestial object caused by the observer's motion and the finite speed of light.^[2][9]

Timeline

• 1588 – a deviation from what is normal or expected.^[2][4]
• before 1594 – literal straying from a course (obsolete by 1830).^[2]
• 1594 – a departure from a moral standard.^[2][6]
• 1615 – a passing impairment of reason; a deviation from a natural type.^[2]
• 1672 – in optics, the failure of rays of light to meet at one focus.^[2]
• 1737 – in astronomy, the apparent shift of a celestial object.^[2]

Meanings

Noun

1. A departure from what is normal, usual or expected: The poor quarter was an aberration in an otherwise strong year.^[9][4][2]
2. A departure from truth or from a moral standard.^[9][4][2]
3. A passing lapse in control of the mind; unsoundness of mind short of insanity.^[9][4][2]
4. (biology) A deviation from the expected natural type, or an instance of it.^[2][4]
5. (optics) A defect in a lens or mirror that stops rays of light from meeting at one focus, so that the image is blurred or has coloured fringes.^[9][4][2]
6. (astronomy) The apparent displacement of a celestial body, caused by the observer's motion and the finite speed of light.^[9][2]
7. (obsolete, 1594–1830) Literal straying or wandering from a course.^[2][8]

Word family

• aberrational
• chromatic aberration
• spherical aberration

Related words

• aberrant
• err

References

1. ^ Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b c d e f g h i j k l m n o p q r s t u v w Oxford English Dictionary Online (accessed March 2026), Oxford: Oxford University Press
3. ^ a b c d The American Heritage Dictionary of the English Language (online 2024), 5th ed., Boston: Houghton Mifflin Harcourt
4. ^ a b c d e f g h Merriam-Webster Unabridged Dictionary (2024), online ed., Springfield, Mass.: Merriam-Webster
5. ^ a b c d e Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
6. ^ a b c d e f Barnhart, Robert K. (1988), The Barnhart Dictionary of Etymology
7. ^ Stevenson, Angus, ed. (2010), Oxford Dictionary of English, 3rd ed., Oxford: Oxford University Press
8. ^ 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.
9. ^ a b c d e f Collins English Dictionary (2023), Glasgow: HarperCollins