Green’s Dictionary of Slang

1. a failure.

1856		B.H. Hall College Words (rev. edn) 205: flummux. Any failure is called a flummux.
1857		‘Ducange Anglicus’ Vulgar Tongue.
1905		‘Central Connecticut Word-List’ in DN III:i 9: flummox, n. A failure.

2. confusion, ‘a state’.

1889

‘’Arry on the Battle of Life’ in Punch 21 Sept. in P. Marks (2006) 137: If you find as yer foe’s in a flummox, will you risk the win and tin.