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

• Lexulous
• Wordscraper
• Wordosaur

adj. superlative form of grumpy: most grumpy.

"• And finally, the title grumpiest man of the week goes to author Howard Jacobson, whose view of modern life doesn't appear to have been lifted by his long-awaited Booker triumph with The Finkler Question."