Green’s Dictionary of Slang

1. a whore [like the dog she ‘hunts around’].

c.1608

Shakespeare Timon of Athens IV iii: Get thee away, and take Thy beagles with thee.

2. (US) a native of Virginia [the popularity of fox-hunting in the state].

1864		Wisc. Jrnl Education 9 328: ...Delaware, Muskrats; Maryland, Buckskins; Virginia, Beagles.
1885		North Amer. Rev. Nov. 433: Among the rank and file, both armies, it was very general to speak of the different States they came from by their slang names. [...] Virginia, Beagles.

3. (US) a nose [the dog’s sniffing abilities].

1926		Wood & Goddard Dict. Amer. Sl.
1933		Ersine Und. and Prison Sl.

4. (US Und.) a sausage, esp. a ‘hot dog’ [pun].

1927		‘Jargon of the Und.’ in DN V 438: Beagles, Sausages; an obvious attempt to invent an original synonym for ‘dogs’.
1936		Mencken Amer. Lang. (4th edn) 580: In virtually all American prisons [...] sausages are beagles or pups.
1950		Goldin et al. DAUL 24/2: Beagles. (P) Sausages.
1960, 1975		Wentworth & Flexner DAS.
1962		Ragen & Finston World’s Toughest Prison 790: beagles – Sausages.
1992		Bentley & Corbett Prison Sl. 66: Beagles Old term for sausages.

5. (US) a journalist [the dog’s sniffing abilities].

1948

T. Thursday ‘Movie Stuff’ in Detective Story Apr. 🌐 I think I’ll let you news-beagles solve this one.

6. (US) a (usu. unattractive) young woman [dog n.² (8)].

1952		(con. WWII) R. Thacher Captain 96: ‘Know where that beagle was pointed? Waste no time, man.’ The Captain laughed. ‘Those dames—’.
1959		A. Zugsmith Beat Generation 134: And what about those beakels [sic] downstairs? [...] they’d fink on their own mother.