cockroach

A cockroach is an insect whose name reached English from Spanish cucaracha. By the 1620s, English speakers had reshaped the borrowed word through folk etymology, making it look like the familiar elements cock and roach—a memorable English disguise for the Spanish name. The Spanish word’s deeper origin is uncertain: one account connects it to cuca, meaning “butterfly caterpillars,” and describes that word as onomatopoeic; another says cucaracha has been argued to come from a 16th-century Caribbean-language word. The name also developed derogatory uses for people, including a dehumanizing label used against Tutsis during the Rwandan genocide.