aberration

ot 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.