Superlative form of stuffy: most stuffy.(adjective)
Wiktionary.org : Text is available under the Creative Commons Attribution-ShareAlike License
Use "stuffiest" in a sentence
"She was so comfortable in the company of the Queen, and under the stuffiest of circumstances, that she felt free to be herself—even if it meant giggling at centuries-old tradition."
"She credited her incredible ad-libbing skills to the years she spent attending embassy cocktail parties with Paul, where she learned to disarm the stuffiest foreign diplomats with her down-to-earth American humor and entertaining anecdotes."
"Thai tom yum is just what the doctor ordered, being both hot and searingly aromatic enough to cut through even the stuffiest of winter colds."