ab•er•ra•tionˌæb əˈreɪ ʃən(n.)

1. deviation from the usual or normal course.

2. deviation from the usual or normal type.

3. deviation from truth or moral rectitude.

4. mental unsoundness, esp. of a minor or temporary nature; mental lapse.

   Category: Psychiatry

5. apparent displacement of a heavenly body, owing to the motion of the earth in its orbit.

   Category: Astronomy

6. any disturbance of the rays of a pencil of light such that they can no longer be brought to a sharp focus or form a clear image.

   Category: Optics

Origin of aberration:

1585–95; < L aberrātiō <aberrā(re) (see aberrant )

ab`er•ra′tion•al(adj.)