Currently most common, widespread, or dominant in a place or time; or the act of being stronger and winning.
From Latin 'praevalere' (to be stronger), from 'prae-' (before) plus 'valere' (to be strong). Used since the 1400s to mean both winning and being widespread.
The 'prevailing winds' blow in the same direction most of the time in each latitude—that's why European explorers could sail to America with the trade winds but had trouble getting back until they discovered the jet stream path!
Complete word intelligence in one call. Free tier — 50 lookups/day.