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 stately: most stately.

"Replied the Prince, ‘Go ye to my father and acquaint him with my case, and fetch us tents, for we will tarry here seven days to rest ourselves till he make ready his retinue to meet us, that we may enter in stateliest state.’ —"

gallantest    solemnest    vice-regal    forty-gun    megalithic