Green’s Dictionary of Slang

cowyard n.

[cow n.1 (2) + pun on SE]

(US) a cheap brothel.

[US] (ref. to 1898) N. Kimball Amer. Madam (1981) 263: On the Coast there were the cow-yard whore, the crib whore, and the parlour house whore. [...] I’ve visited cow-yards where there were two hundred-and-fifty to three hundred whores at work.
[US](con. 1870s–1910s) H. Asbury Barbary Coast (2002) 243: In that portion of the red-light district which formed a part of the Barbary Coast, there were three main types of brothel — the cow-yard, the crib, and the parlor house.

SE in slang uses

In compounds

cowyard cake (n.) [it is supposedly reminiscent of a cowpat + attendant flies]

(Aus.) a type of cake or bun that contains sultanas.

[Aus]Baker Aus. Speaks.
cowyard confetti (n.) [euph. for bullshit n. (1)]

(Aus.) nonsense, rubbish.

[Aus]Age (Melbourne) 4 Aug. 16: ‘Cowyard confetti’ my long deceased great-uncle would have called it when in polite company [GAW4].