aberration

1. (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.countableuncountable

2. (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.countableuncountable

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.broadlycountableuncountable

4. (fantasy, roleplaying games) Any creature with supernatural powers not found in the organized classes of beings in a given setting.Examples: "Only by submitting to the aberration could the human traders travel safely through the territory of Zularn."countableuncountable

5. (zoology, botany) Atypical development or structure; deviation from the normal type; an aberrant organ.countableuncountable

6. (medicine) A deviation of a tissue, organ or mental functions from what is considered to be within the normal range.countableuncountable