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

• Lexulous
• Wordscraper
• Wordosaur

n. Someone who plays the tuba

""They look after their regulars very well – that's the secret," said Martin Knowles, a tubist from the English National Opera, sipping a pint of Darkstar Hophead with colleagues under the whir of a fan."

tubaist