• Etymology Today from M-W: hoity-toity \hoy-tee-TOY-tee: thoughtlessly silly or frivolous : flighty
: marked by an air of assumed importance : highfalutin

Today we most often use "hoity-toity" as an adjective, but before it was an adjective it was a noun meaning "thoughtless giddy behavior." The noun, which first appeared in print in 1688, was probably created as a singsongy rhyme based on the dialectal English word "hoit," meaning "to play the fool." The adjective "hoity-toity" can stay close to its roots and mean "foolish" (". . . as though it were very hoity-toity of me not to know that royal personage."-W. Somerset Maugham, The Razor’s Edge), but in current use it more often means "pretentious."

Also, from Slate: Where does the phrase "pie-in-the-sky" come from?
And from the London Guardian: OED editor John Simpson's favorite words with unusual origins

• Previous E.T.