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

• Lexulous
• Wordscraper
• Wordosaur

ad. Indisputably; certainly, definitely; without the possibility of argument or debate.

"But the judge maintained that the jurors 'ability to impartially decide an "inarguably" high-profile case could be impaired by unsolicited interruptions."