Cheating on your wife or girlfriend, especially if in the process of cheating, you disappear for a few days and say you are going someplace where it is impossible to be reached. Can also be used on a woman to say that she's cheating.

Same meaning as the other two entries here at UrbanDictionary.com: "Hiking in Appalachia" and "Hiking in the Appalachian Mountains", except that that "hikin' the Appalachian Trial" sounds better.
guy 1: "Where's Dave? I thought he he was going to play golf with us today."

guy 2: "He told his wife he had to work the weekend, but I think he's hikin' the appalachian trail. He was flirting all week with that new chick in accounting"

-or-

guy 1: "Where has your girlfriend been lately?"
guy 2: "I dumped her ass! Caught her hikin' the appalachian trail, and that was it for that slut!"
by rpompeii June 29, 2009
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Going AWOL on your job to have a clandestine affair.
"Where has Joe been for the last three days? He didn't tell us that he'll be taking time off!"

"Uh... He's hiking the Appalachian Trail."

"Oh. In that case, where's the pink slip?"
by L-R- July 17, 2009
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"Hey, where did our governor go?"
"He told me he was hiking the appalachian trail..."
"Hope he takes protection."
by girlmain July 14, 2009
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As unintentionally coined by South Carolina Govenor Mark Sanford, who in June 2009 disappeared for a few days to Argentina to visit his mistress, while his staff was left with the task of covering up his affair by alleging the Govenor was taking time off to hike the Appalachian Trail.

"Hitting the Appalachian Trail" is a phrase that can be used to describe a politician having an affair. Much like, "Sorry, honey, I was working late at the office." This phrase may achieve the popularity of other politico lingo, such as using the suffix "-gate" when discussing a political scandal.
"Despite the fact that former President Clinton hit the Appalachian Trail a few times during his presidency, many still remember him as a successful president."

"Many Democratic lawmakers are disappointed that numerous Republicans have been caught hitting the Appalachian trail in the past few years, yet still insist upon being the party of morality and conservatism."
by wordstress913 June 25, 2009
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An unnecessarily bizarre and implausible cover story for marital infidelity.
I'm sorry, Carol, I can't go to your mother-in-law's Tupperware party this evening. I'm hiking the Appalachian Trail with that new secretary from the office... in Argentina.
by Abolish the Fed June 24, 2009
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To travel to Argentina to bang your mistress, while your gubernatorial staff back in South Carolina lies to the press about your whereabouts (see Sanford, Mark).

To cheat on your wife.
"Jane filed for divorce when she caught her husband hiking the Appalachian Trail with the babysitter."
by Palmetto Ghetto June 24, 2009
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Spending time with your mistress.
"Where are you going, Governor?"
"I'll just be hiking the Appalachian Trail with Lupe for the next few days."
by hayes6 June 24, 2009
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