Green’s Dictionary of Slang

an odd circumstance, a surprise; often as rum or rummy start.

1835		‘Moses Samuels And The Nasty Little Vomans’ in Secret Songster 12: Oh, dear, dis was a pretty start, ve couldn’t valk at all.
1838		Comic Almanack May 137: Crikey! here’s a pretty start!
1853		Dickens Bleak House (1991) 105: Being asked what he thinks of the proceedings, [Little Swills] characterises them (his strength lying in a slangular direction) as ‘a rummy start’.
1860		Hotten Dict. of Modern Sl. etc. (2nd edn) 227: START, a proceeding of any kind; a ‘rum start,’ an odd circumstance.
1873		Sl. Dict.
1883		J. Greenwood Tag, Rag & Co. 143: One of them remarked that of all the queer starts he’d ’eard tell of, that was the queerest.
1890–1904		Farmer & Henley Sl. and Its Analogues.
1905		Marvel III:53 11: Well, this is a rummy start!