Champú, attested in Spanish as far back as 1908, is one of many words borrowed from English in the 20th century. Unlike most recent borrowings, though, shampoo wasn’t originally an English word, or even a word that English acquired from French or Latin or Greek. Instead, shampoo entered English when the British colonized India in the 1700s. The word came from champo, a Hindi imperative of the verb champna, which meant ‘to press, to knead.’ Originally named for the massaging that takes place when someone works a cleanser into the hair, English shampoo has come to refer primarily to the hair cleanser itself, and that is the sense of the word that Spanish carried over as champú. English, with its flexible parts of speech, lets shampoo be a verb as well as a noun, but Spanish has no standalone verb based on champú, no *champuar or *champuear. Instead, Spanish speakers have to resort to a phrase like dar un champú.
© 2011 Steven Schwartzman