An Enormity

1. (obsolete) Deviation from what is normal or standard; irregularity, abnormality.
2. (uncountable) Deviation from moral normality; extreme wickedness, nefariousness, or cruelty. [from 15th c.]

3. (countable) A breach of law or morality; a transgression, an act of evil or wickedness. [from 15th c.]
4. (uncountable) Great size; enormousness, hugeness, immenseness. [from 18th c.]

Enormity as a synonym for enormousness is sometimes considered an error, though other usage guides hold that there is little basis for the distinction. Both words ultimately go back to the same Latin source word ēnōrmis meaning “deviating from the norm, abnormal”.

(deviation from what is normal or standard): anomalousness, oddness, weirdness; strangeness

(deviation from moral normality): atrociousness, depravity, immorality; villainy

(a breach of law or morality): desecration, violation

(great size): immensity, prodigiousness