Green’s Dictionary of Slang

1. skittles, esp. as played in a public house.

1828		‘Jon Bee’ Living Picture of London 263: The charms of nine-pins – whether this be of skittles, knock-’em-downs, bowl-and-tip, dutch-pins, or the more sturdy four-corners.
1854		T. Buckley Sydenham Greenfinch 103: The value of rotten eggs, dead kittens, knock-me-downs.
1872		Fun Sept. n.p.: A man, the proud possessor of knock-me-downs, was brought up at Wandsworth police-court the other day for plying his trade on Putney Common [F&H].
1876		C. Hindley Life and Adventures of a Cheap Jack 59: Joe dragged on [...] acting as supernumerary potman, or getting a few halfpence at setting up the pins at knock-em-downs.

2. a coconut shy.

1937–84

Partridge DSUE (1984) 655: from ca. 1825.