This word is acceptable for play in the UK dictionary that is being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

n. A collapsible top hat

"Ask little Tom Prig, who is there in all his glory, knows everybody, has a story about every one; and, as he trips home to his lodgings in Jermyn Street, with his gibus-hat and his little glazed pumps, thinks he is the fashionablest young fellow in town, and that he really has passed a night of exquisite enjoyment."

gibbous