Green’s Dictionary of Slang

1. (Aus./N.Z., also moe, mou, mow) a moustache.

1895		Coburg Leader (Vic.) 6 July 1/7: Fred W., the spoony young man, should-get some hair restorer to grow a moe.
1895		C. Crowe Aus. Sl. Dict. 51: Mou, a moustache.
1896		Coburg Leader (Vic.) 15 Feb. 5/4: They say he has bought a 6d. bottle of hair restorer for his mo.
1900		Bulletin (Sydney) 31 Mar. 11/1: [P]assing round the wearer’s face – a heavy silver chain, which after consideration I decided was intended to keep his jawbone in position and possibly to help his ‘mo.’ to maintain that fiercely-horizontal twist.
1911		E. Dyson ‘Susie Gannon’s Young Man’ in Benno and Some of the Push 106: But what iv the down droopin’ yaller mo?
1912		Sport (Adelaide) 27 July 14/1: They Say [...] That Tom F., with his ‘mow’ off, out to make a good minister.
1913		Sport (Adelaide) 26 Apr. 12/3: They Say [...] That Nopper P must have let the razor slip when he shaved his mou off.
1914		Sport (Adelaide) 3 Apr. 4/1: They Say [...] That Florrie uses Doxo for her moe.
1915		F. Garrett diary 18 Nov. 🌐 He is a Corporal and has a Charlie Chaplin mo.
1924		G.H. Lawson Dict. of Aus. Words And Terms 🌐 MO. — Contraction of [...] moustache.
1925		Sun. Times (Perth) 1 Jan. 4/7: The time when he first grew a mo.
1938		X. Herbert Capricornia (1939) 273: That’s Sam Snigger, the lanky old coot with the ginger mo.
1946		D. Stivens Courtship of Uncle Henry 18: ‘I’ll warm your pants for you, young shaver, if you touch that dang collar,’ he’d warn me, the ends of his long black mo shaking.
1959		G. Hamilton Summer Glare 139: A tall thin joker [...] with a la-te-da little mo.
1986		C. Bowles G’DAY 7: MACKA: Wooden mine givin that one. She's with some turkey. SHANE: The smooth bastard with the mo?
1992		A. Duff One Night Out Stealing 85: Jube [...] Boob-walkin, shaded, fat walrus mo and a few days’ stubble.
2001		(con. 1945–6) P. Doyle Devil’s Jump (2008) 65: His dark hair was slicked back, his thin mo trimmed.
2003		McGill Reed Dict. of N.Z. Sl. 136: mo A moustache. ANZ late C19.

2. a moment, a second; often as half a mo n.¹

1905		‘Doss Chiderdoss’ ‘An Improved Understanding’ in Sporting Times 14 Jan. 1/4: If you hadn’t asked for her, I’ll have you to know, / You’d have gone through that window in less than a mo’.
1908		J. Gunn We of the Never-Never (1962) 104: In ‘half a mo’ the seals were broken, and the mail-matter shaken out.
1921		N&Q 12 Ser. IX 424: Arf a Mo’. Wait a bit.
1941		V. Hodgson Diaries (1999) 22 Feb. 129: He got rid of the other customers and then whispered, ‘Wait a mo.’ I found half a pound of cheese being thrust into my bag with great secrecy and speed!
1950		A. Buckeridge Jennings Goes To School 216: Come outside on the landing a mo’.
1965		G. Melly Owning Up (1974) 230: Will this do for the mo, cock?
1971		N. Armfelt Catching Up 181: Just a mo.
1988		T. Harris Silence of the Lambs (1991) 130: Just a mo’, sweetheart.
1996		J. Byrell Lairs, Urgers & Coat-Tuggers 287: Thel has to spend a penny and gets Ken to hang on a mo just up from the ladies’ brasco.
1999		K. Sampson Powder 111: Wants to see you when you get a mo.
2003		N. Griffiths Stump 24: Startling extremes of the chronic dipso who just happens not to be drinking at the mo.
2019		C. Hammer Silver [ebook] ‘Catch you in a mo’.

3. (US) a month.

1918		R. Lardner Treat ’Em Rough 70: I was the only one that passed up all that jack to work for Uncle Sam at $30.00 per mo.
1952		(con. 1948) G. Mandel Flee the Angry Strangers 93: ‘How long a trip?’ Carter asked. ‘Six moes.’.

4. (US campus/UK teen) a homosexual [abbr. homo n.² ].

1967–8		Baker et al. CUSS 158: Mo An effeminate male. A homosexual.
1987		G.A. Fine With the Boys 169: Mo, n. Homosexual.
1997–2000		College Sl. Research Project (Cal. State Poly. Uni., Pomona) 🌐 Mo (noun) 1. A homosexual. 2. Used among friends as a teasing vocative.
2001		OnLine Dict. of Playground Sl. 🌐 mo n. a homosexual.
2012		Independent 24 Jan. 36/1: Elderly synonyms for ‘homosexual’ (poofter, queer, mo).

5. momentum.

2008

W.D. Myers Game 180: The mo changed big-time and their coach called a time-out.

6. see motherfucker n.