Green’s Dictionary of Slang

enthuzimuzzy n.

enthusiasm.

1832		Satirist (London) 30 Dec. 421/1: [T]he health of the sultan was drunk with much cordiality, the Grand Turk, on his part, proposing and drinking that of our patriotic William, with equal entousy mousy.
1909		J. Ware Passing Eng. of the Victorian Era.