-The season originally used to be called harvest. In fact, most Germanic languages have preserved derivatives of the word to mean fall/autumn.
-Fall is often thought of as a North American word whereas autumn is preferred in other English-speaking countries. However, it's originally a British word. Fall replaced harvest around the time of Shakespeare and was preserved in the US and Canada during early British colonization. The British simply replaced the word with autumn over time.
It's a bit strange when you think about it because the names for the other three seasons are of Germanic origin. But for some reason the British adopted a word of clear French/Latin origin for a particular season.