Green’s Dictionary of Slang

1. a testicle.

1896

Farmer Vocabula Amatoria (1966) 29: Ballottes (les), f. 1. The testes; ‘the cannon-balls’.

2. (US short order) in pl., crullers.

1887

‘Dict. of Diningroom Sl.’ in Brooklyn Daily Eagle 3 July 13: ‘Cannon balls,’ are crullers.

3. (US, also cannonball train) an express train.

1882		Topeka Dly Capital (KS) 4 Oct. 4/5: The cannon-ball train came down from the east.
1883		Dodge City Times 4 Oct. in Miller & Snell Why the West was Wild 456: The cannon ball [...] pulled into Coolidge shortly before one o’clock.
1894		J. London Tramp Diary in Jack London On the Road (1979) 55: We caught the ‘Cannon ball’ as she slowed up at the crossing.
1906		J.W. Carr ‘Words from Northwest Arkansas’ in DN III:ii 129: cannonball, n. A fast through train [...] ‘The happy couple left on the cannonball for St. Louis.’ – Fayetteville newspaper.
1913		L. Light Modern Hobo 47: The Cannon Ball will soon be in.
1918		‘Hoochey, Coochhey Hilda’ in J.J. Niles Singing Soldiers (1927) 26: French cannon-ball goes so goddam fast, / Can’t never count de cars as they wizzes past.
1925		G.H. Mullin Adventures of a Scholar Tramp 310: She was the Banner Limited, a cannon-ball making only a few stops.
1927		W. Edge Main Stem 17: He would [...] find out the hour of an express departure, and would then lay his plans to ‘deck the cannon-ball on the fly’.
1930		‘Dean Stiff’ Milk and Honey Route 201: Cannon ball — A fast train.
1933		Blind Willie McTell ‘My Baby’s Gone’ 🎵 She even left me / Says she riding that Cannonball.
1940		in Campbell & Campbell War Paint 178: [aircraft nose art] ‘Wabash Cannon-Ball IV’.
1958		Hughes & Bontemps Book of Negro Folklore 390: I’m gonna buy me a pistol just as long as I am tall. [...] Kill my man and catch the Cannon Ball.
1960, 1975		Wentworth & Flexner DAS.
1970		E. Thompson Garden of Sand (1981) 281: He sang: From the broad Atlantic Ocean / To the wide Pacific shore / She’s coming down from Birmingham / On the Wabash Cannonball.

4. (US Und.) a smaller safe that is held within a larger one; occas. attrib.

1899		Anaconda Standard (MT) 25 July 8/7: They are tearing out ceilings and walls preparatory to [...] fixing a place for the new cannonball safe.
1907		Butte Dly Post (MT) 5 Jan. 1/3: The sale included the cannonball safe, bank desk and fixtures.
1912		Anaconda Standard (MT) 6 Sept. 8/5: The ‘Cannonball’ safe of the Miners savings and Trust Company was found uninjured.
1924		G. Henderson Keys to Crookdom 67: But with grease the yegg could not get a manganese ‘cannon-ball’ safe, the spheroids that are found in many big banks.
1933		Ersine Und. and Prison Sl.
1950		Goldin et al. DAUL 40/1: Cannonball. 1. A small round safe frequently found inside a vault or a larger safe.

5. (US Und.) a message sent out of jail by a convict.

1929		V.W. Saul ‘Vocab. of Bums’ in AS IV:5 338: Cannon ball — A message sent by one in jail via a jail trusty.
1949		Monteleone Criminal Sl. (rev. edn).
1960, 1975		Wentworth & Flexner DAS.

6. (US) a superior person or one who claims to be so.

1949		Hal Ellson Duke 75: He’s a real cannonball.
1962		(con. 1930s) H. Simmons Man Walking On Eggshells 21: You poppa’s a cannonball.
1963		L.F. Freed Crime in S. Afr. 106: A ‘big shot’ or ‘cannon ball’ is an underworld leader.

7. (US drugs) a mixed injection, e.g. of heroin and cocaine or morphine and cocaine.

1959		J.E. Schmidt Narcotics Lingo and Lore.
1975		Hardy & Cull Drug Lang. and Lore.