To 'hitchhike' or walk along a roadway requesting rides from passing cars by holding an outstreched thumb pointed in the direction of travel. One may also display the destination on a sign to assist the process.
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To travel without a set course or time frame, more emphasis is placed on the journey, hanging out with people you meet and exploring diversions along the way. The original intended destination may not even be reached and possibly forgotten about along the way.
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A form of guitar or bass improvisation that relies heavily on the the thumb on the rythmic hand.

When you eat dirt for the first time and leave your family to build a shack in the woods