Pumpernickel means "devil's fart", a definition accepted by the publisher Random House, and by some English language dictionaries, including the Merriam-Webster Dictionary. The American Heritage Dictionary adds "so named from being hard to digest". A variant of this explanation is also given by the German etymological dictionary "Kluge" that says the word is older than its usage for the particular type of bread, and may have been used as a mocking name for a person of unrefined manners ("farting Nick") first. The change of meaning may have been caused by its use as a mocking expression for the (in the eyes
What Love Is Made Of three minutes and fifty-five seconds (3:55), "What Love Is Made Of" is an uptempo dance and house track that has been described as "rave-y" and "trance-y". Its instrumentation contains the sounds of pianos and synthesizers. Jordan Sargent of "Spin" observed that it continued the musical style first introduced in Katy's 2012 extended play (EP), "Danger EP", which was "straight-forward house". Idolator's Sam Lansky compared her performance in the song to recording artist Siobhán Donaghy. Critical response to "What Love Is Made Of" was generally positive: most critics noted Katy's vocal performance and commended its sound. Siân Rowe from "NME" was