The word peach comes from the Old French word pesche, which meant "peach tree" as well as "peach". In an later form of Latin, this was pesca, and in the classical form, it was persica. Persica was part of the phrase malum persicum, meaning "Persian apple" and a loan from Greek Persikon malon. Yes, a peach was considered an exotic type of apple. Malon means "apple", and, obviously Persikon means Persian. This may be conjugated to Persis, which meant plain ol' "Persia" and is the source of our current word for "Persia" as well. Persis comes Old Persian parsa, their self-apellation which likely derives from the Median language and, by extent, Indo-Iranian and Proto-Indo-European. Peachy as an adjective has been around since the 1590s but it didn't mean "neat" or "attractive" until 1900. Peachy keen, the ultimate 50s phrase, was coined in 1951. Usages of all these phrases are rising after recent falls in popularity (peach peaked in the mid-1910s)
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.