noun

1. The act of wandering; deviation from truth, moral rectitude; abnormal; divergence from the straight, correct, proper, normal, or from the natural state.

   "aberration of character"

2. 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. 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.

4. A partial alienation of reason.

5. A mental disorder, especially one of a minor or temporary character.

6. Atypical development or structure; deviation from the normal type; an aberrant organ.

7. A deviation of a tissue, organ or mental functions from what is considered to be within the normal range.