I. noun 1. a departure from what is normal, usual, or expected, typically an unwelcome one • they described the outbreak of violence in the area as an aberration.
• I see these activities as some kind of mental aberration.
[Biology] a characteristic that deviates from the normal type
• colour aberrations.
[Optics] the failure of rays to converge at one focus because of a defect in a lens or mirror.
[Astronomy] the apparent displacement of a celestial object from its true position, caused by the relative motion of the observer and the object.
II. derivatives aberrational adjective
– origin late 16th cent.: from Latin aberratio(n-), from aberrare ‘to stray’ (see aberrant).