To me the word expedition get used very easily to describe a big trip. Personally I think few bicycle trips can be considered an expedition because you'll usually be on some kind of road and therefore within a day or two of water/food/help and there's a good chance than from time to time a vehicle will pass that can get help out if you're in the shoot...
An expedition to me is a multi day/week/month trip where you are totally self sufficient. Even in the most remote parts of my trip I came across a farm/vehicle driver at least once a day.
I am deffinately on a trip, and have used said vehicle to save my life once, sanity twice and saved me from a shoot day several times

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