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

(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.

A small periodical change in the apparent positions of stars and other heavenly bodies, caused by the combined effect of the motion of light and the motion of the observer, and also refers to the tendency of light rays to preferentially strike the leading face of a moving object.

(fantasy, roleplaying games) Any creature with supernatural powers not found in the organized classes of beings in a given setting.

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

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

(electronics) A defect in an image produced by an optical or electrostatic lens system.