enormity / enormousness
Great wickedness vs. great size.
Enormity means great wickedness, or a grave wrong: the enormity of the crime. A common error is to use enormity to mean great size, as in the enormity of the stadium. For great size, use immensity or enormousness: the immensity of the stadium.
Examples
UseThe audit revealed the enormity of the fraud. (its wickedness, not its size)
UseVisitors remarked on the enormousness of the warehouse. (its size)
AvoidVisitors remarked on the enormity of the warehouse. (if you mean its size)
Dictionaries now also list enormity meaning “great size.” However, many people still consider this use an error, and they judge the speaker who uses enormity this way.