Green’s Dictionary of Slang

wibbly-wobbly adj.

uneven.

1915		Sport (Adelaide) 8 Jan. 5/6: Sorry she has that wibbly-wobbly walk at all times.
1927		(con. 1910s) S. Lewis Elmer Gantry 359: Your wibbly-wobbly emphasis on Heaven and your fear to emphasise the horrors of Hell.
1999		Guardian G2 21 June 13: The wibbly-wobbly streetscape of Margate.