aberration

Etymology

A learned borrowing from Latin aberrātiō (“relief, diversion”), first attested in 1594, from aberrō (“wander away, go astray”), from ab (“away”) + errō (“wander”). Compare French aberration. Equivalent to aberrate + -ion.

noun

1. The act of wandering; deviation from truth, moral rectitude; abnormal; divergence from the straight, correct, proper, normal, or from the natural state.
   the aberration of youth
   aberrations from theory
   aberration of character
   A derailment which occurred on April 18 last between Laindon and Pitsea on the London Tilbury & Southend Line was caused by a lengthman who in a moment of aberration clipped a set of spring catch points in the derailing position, concludes Col. J. R. H. Robertson in his report …. 1961 December, “Talking of Trains: Derailment near Laindon”, in Trains Illustrated, page 717
2. (optics) The convergence to different foci, by a lens or mirror, of rays of light emanating from one and the same point, or the deviation of such rays from a single focus; a defect in a focusing mechanism that prevents the intended focal point.
3. (astronomy) A small periodical change of the apparent positions of the stars and other heavenly bodies, due to the combined effect of the motion of light and the motion of the observer.
   1. (astronomy, by extension) The tendency of light rays to preferentially strike the leading face of a moving object (the effect underlying the above phenomenon).
4. A partial alienation of reason.
   Occasional aberrations of intellect 1819, John Lingard, The History of England, From the First Invasion by the Romans to the Accession of Henry VIII
   We see indeed the aberrations of unruly appetite 1828, Isaac Taylor, The balance of criminality
5. A mental disorder, especially one of a minor or temporary character.
6. (zoology, botany) Atypical development or structure; deviation from the normal type; an aberrant organ.
7. (medicine) A deviation of a tissue, organ or mental functions from what is considered to be within the normal range.
8. (electronics) A defect in an image produced by an optical or electrostatic lens system.