Some historians believe that Posh means “port out starboard home” and was first introduced on P and O ocean liners between Britain and India in the days of the Raj. Wealthy passengers would ask for better cabins to avoid the sun’s glare and had their tickets stamped with “P.O.S.H.”
However, there is no hard evidence for this popular theory. In the early 1900s, “posh” became an English term meaning “stylish, smart, elegant, or classy.”