When two guys have sex with the same girl in the same day (or within a 24 hour period) at different times (probably hours apart). This does not include a Chinese Fires Drill, tag-team, or "switcharoo" or anything else that just means one is "waiting for their turn". It can not be planned or have any pre thought. It must happen naturally and without pushing. As with anything, consent is necessary and do not be a fuck about it. Lewis and Clark were the two best friends that anyone could have and had to spent a good amount of time with Sacagawea, and who knows what really happen.
"_____ had sex with her in the morning and _____ had sex with her at night, they have officially been dubbed 'Lewis and Clark".

"____ and _____ have 'Lewis and Clarked' ______.

"_____ and ______ have done 'A Lewis and Clark'.
by $tingRay August 31, 2014
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Where two people pose for a picture to imitate the Lewis and Clark Historic Trail signs where one person is pointing while the other looks on. Usually done at a point along their historic trail.
by historyisawesome January 19, 2014
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(v.) To find one's way without using a map.
I forgot the atlas but I just Lewis and Clarked it and got there anyway.
by Ryan Byrne December 3, 2007
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To embark upon an expedition of any kind, whether short or long, and without regard to the use of nagivation devices.
Since the art festival was downtown, Jack and Jill decided to Lewis and Clark over and check it out.

On the weekends, they like to Lewis and Clark around town, finding new restaurants to try and places to see.
by Prolixity November 18, 2009
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A game played by two people that involves the 'exploration' of each others bodies. Game is usually played by using hands, and on occasion, tongues but once you cross into the danger zone, its no longer lewis and clarking, then its officially a hook-up.
Girl one: Omgshhhh last night was amazing!!!
Friend: So did you guys hook up??
Girl one: No, but there was definitely some lewis and clarking going on ;D
by summerisamazing =] April 3, 2009
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An act of the woman using her hands to masturbate the male by first using the penis as a rowing device while both male and female shout out "What's over there? " until the male is about to ejaculate, which then the male flips the female on her back, lifts both of her legs up and uses her ass as a chair while he tries to stuff his testicles inside of her anus, this part is called the "Treaty." When the male successfully stuffs his testicles inside the female's anus, the male quickly masturbates again, upon the moment he ejaculates, he kicks both legs back and shoots the female off of his now blue, blood starved balls and quickly stamps them on a piece of paper and begins to draw a map with the sweat, feces, and blood that cover his balls. The male quickly rolls the map up and saves it. This is called the Lewis and Clark
Me and my friend want to Lewis and Clark, but the drawer smells too bad already
by EtnaRee-l October 27, 2013
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A variation of the Patrick Swayze, but with two males both sticking their penises into one girl's nostrils (one is each nostril)
Groff and the mexican sure want to Lewis and Clark Hugh...
by Casey January 16, 2004
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