When someone is caught lying. How now is self explainitory. Brown Cow means that they are a liar. Works incredibly well if they are exposed for their lie.
Guy 1: Hey, I know what the capital of Illinois is. It's Chicago.

Guy 2: It's Springfield. How now brown cow?
by gbee93 March 23, 2011
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Those four words roll off the tongue as a lighthearted way of asking "What's up? What's next?" And that tripping lightly stuff makes sense, since "How now, brown cow" has its origin in elocution, where the phrase was used to demonstrate properly rounded vowels.
Ron: How now, brown cow?

Paul: Not much. Just on my way to catch a movie with my girl.
by MoonCricket March 27, 2005
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"How now brown cow" is a phrase used in teaching a style of public speaking in which gesture, vocal production, and delivery are emphasized to demonstrate rounded vowel sounds.
Teacher: Work on your vowel sounds.

Student: "How now brown cow?"

Teacher: Rounder, please...
by Adm_Hawthorne July 25, 2006
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It actually means, "What's next?" I read that on the Merriam Webster Dictionary site after trying to look it up here.
"How now, brown cow?"

"You're going to turn into a purple cow."

by Sara Harmon February 22, 2006
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lighthearted way of asking "What's up? What's next?"

Has its roots in prohition era referring to when a keg (brown in those days) was empty, "well, what are we gonna do now..."
"It seems as though the rave is over, Winnifred" says Penelope.
"How now, brown cow?" says Winnfred inquisitively
"Let's get poprox!"
by TexasCaveman July 31, 2005
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