Green’s Dictionary of Slang

1. the vagina; one of a number of terms equating it with a threat to the penis; thus a prostitute.

1859		G.A. Sala Twice Round the Clock 94: A two-hour speech at the meeting for the suppression of street ‘catch-’em-alive-O’s’.
1890–1904		Farmer & Henley Sl. and Its Analogues.
c.1904		A. Crowley Snowdrops from a Curate’s Garden 25: The amorous and quick-witted lad, placing his feet together, made a capital catch-‘em-alive-o for his horny flip-flap.

2. a fly-paper; also attrib.

1856		Lloyd’s Wkly Newspaper 17 Aug. 12/2: he was a ‘holy show;’ he was covered all over with fly paper, or what are technically called Catch-’em-alive Os’.
1861		(con. 1840s–50s) H. Mayhew London Labour and London Poor III 30/2: There’s lots of boys going silling ‘ketch ’em alive oh’s from Golden Lane and Whitechapel. [Ibid.] 32/1: ‘We are called in the trade,’ said the father, ‘fly-paper makers.’ They used to put a nice name to things once [...] but now they use merely the word ‘fly-papers,’ or ‘fly-destroyers,’ or ‘fly-catchers,’ or ‘catch ’em alive, oh’.
1873		Bradford Obs. 4 Nov. 4/1: A man might as well hawk horniments-for-yer-fire-stove, or ketch-’em-alive-oh’s.
1876		J. Greenwood Low-Life Deeps 269: A man might as well hawk [...] ketch-’em-live-oh’s.
1884		Ally Sloper’s Half Holiday 21 June 61: [caption] Sloper’s Patent Ketch-’em-alive-oh! really does attract flies.
1887		‘A Plain Woman’ Poor Nellie I 239: There are some to whom a novel seems to be exactly like one of those Catch-’em-all-alive-O! flypapers.
1889–90		Barrère & Leland Dict. of Sl., Jargon and Cant.
1896		Regiment 25 July 263/1: Ex- Sergeant-Majors and Colour-sergeants are acting in such capacities as tram drivers, and park-keepers, even selling fly-papers (‘catch ‘em alive ’O’).

3. a mousetrap.

1865

Watford Obs. 10 June 4/5: There are [...] the old fashioned gin trap, the thoroughfare trap, the ‘catch-’em-alive-O,’ the self-acting [etc].

4. a small comb.

1860		Hotten Dict. of Modern Sl. etc. (2nd edn).
1873		Sl. Dict.