The word left, as in the direction, has a fascinating etymology. The farthest back we can trace it is to the Proto-Germanic term luft, which meant "worthless or weak" and may be from the Proto-Indo-European root laiwo, or "conspicuous". This later disintegrated into Old English as lyft (no, not the ride-hailing service), which still meant "weak". As the spelling changed to modern, so did the definition: since the left side is weaker on many people, the word left was used to describe that general direction. This next part is very interesting: the definition of left as describing liberals, Democrats, and socialists hails back to the days of the French revolution, where the reactionary and conservative nobles sat to the right side of the President in the National Assembly, leaving the liberal Jacobins and Montagnards to be seated on the left. This usage was later coined by a historian in the mid-nineteenth century, and has stuck since.
Adam Aleksic, a freshman studying linguistics at Harvard University, has been described as the internet's sixth most famous etymologist. He has disturbing interests in words, vexillology, geography, board games, limericks, and law, and he loves writing about himself in the third person.
The Etymology Nerd