Green’s Dictionary of Slang

(Aus./US) nonsense, rubbish.

1915		R. Bolwell ‘College Sl. Words And Phrases’ in DN IV:iii 234: meadow dressing, n. incredible nonsense.
c.1943		S .J. Baker Aus. Vulgarisms [t/s] 11: meadow mayonaise: Nonsense, humbug. A fanciful elaboration of bullsh.
1951		D. Stivens Jimmy Brockett 92: Jimmy Brockett was a terrible bull artist. I knew him pretty well and I chyacked him about it one day. ‘Look here, brother, [...] you bet I spread a bit of meadow mayonnaise around.’.
1959		Baker Drum.
1965		Minneapolis Star (MN) 9 Feb. 32/1: He thought he was a bit of all right but the rest of us thought his talk was meadow mayonnaise.