on Mental Floss:
Here’s an ambiguous sentence for you:
“Because of the agency’s oversight, the corporation’s behavior was sanctioned.”
Does that mean, “Because the agency oversaw the company’s behavior, they imposed a penalty for some transgression,” or does it mean, “Because the agency was inattentive, they overlooked the misbehavior and gave it their approval by default”?
We’ve stumbled into the looking-glass world of contronyms—words that are their own antonyms.