aberration
noun
[ ˌabəˈreɪʃ(ə)n ]
• 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"
Similar:
anomaly,
deviation,
divergence,
abnormality,
irregularity,
variation,
digression,
edge case,
freak,
rogue,
rarity,
quirk,
oddity,
curiosity,
mistake,
eccentricity,
transgression,
straying,
lapse,
aberrancy,
Origin:
late 16th century: from Latin aberratio(n- ), from aberrare ‘to stray’ (see aberrant).
