Definition of: aberration

(ab′ə·rā′shən) noun
1. Deviation from a right, customary, prescribed, or natural course or condition; wandering; error.
2. Partial mental derangement.
3. Optics The failure of a lens or mirror to bring all light rays to the same focus: called chromatic aberration when due to different refrangibility of light of different colors, and spherical aberration when due to the form of lens or mirror.
4. Astron. An apparent displacement of a heavenly body, due to the effect of relative motion upon the light coming from it.
5. An abnormal structure; a deviation from a standard type: a chromosomal aberration. [<L aberratio, -onis <aberrare. See ABERRANT.]