This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. The semantic relation between antonyms; the quality of being antonymous.

n. the semantic relation that holds between two words that can (in a given context) express opposite meanings

"Atlantic Blog identifies the antonymy for the typically academic Heidegger, the "ordinary business manager" Victor Kugler."

synonymy   

semantic relation