Green’s Dictionary of Slang

1. a piano.

1943

Larne Times 4 Mar. 4/5: The piano, which used to be the Gertie Gitana, is now the Count Ciano‘.

2. a banana.

1960		J. Franklyn Dict. of Rhy. Sl.
1969		S.T. Kendall Up the Frog.
1992		R. Puxley Cockney Rabbit.
2002		Pete’s Aussie Sl. Home Page 🌐 Gertie Gitana: banana.