- (astronomy) A small periodical change of position in the stars and other heavenly bodies, due to the combined effect of the motion of light and the motion of the observer. [Mid 18th century.]
- (zoology, botany) Atypical development or structure; deviation from the normal type; an aberrant organ. [Mid 19th century.]
- (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. [Mid 18th century.]
- A mental disorder, especially one of a minor or temporary character. [Early 19th century.]
- The act of wandering; deviation from truth, moral rectitude; abnormal; divergence from the straight, correct, proper, normal, or from the natural state. [Late 16th century.]
"the aberration of youth, aberrations from theory, aberration of character"
- A partial alienation of reason. [Early 19th century.]
- (medicine) A deviation of a tissue, organ or mental functions from what is considered to be within the normal range.