A beetle-like scavenging insect with long antennae and legs. Several tropical kinds have become established worldwide as household pests.
This noun first appeared in the form cacarootch in The generall historie of Virginia, New-England, and the Summer Isles (1624), by John Smith (1580-1631), soldier and colonial governor. In the book titled The generall historie of the Bermvdas, now called the Summer Iles, the author wrote:
Concerning vermine and noisome creatures [...]. The Musketas and Flies are also too busie, with a certaine India Bug, called by the Spaniards a Cacarootch; the which creeping into Chests they eat and defile with their ill-sented dung.
This may represent Spanish cacarucha, a variant form of cucaracha, said to be derived from cuca, cuco, denoting the caterpillar of certain moths. However, cacarucha represents more probably the adaption of kakalaka, a Caribbean name for the cockroach. Spread by the Portuguese, this Caribbean name was adopted in Dutch by assimilation to the existing word kakkerlak, meaning despicable person. The Dutch kakkerlak was in turn adapted in French as cancrelat by association with cancre, meaning crab, and figuratively dunce and avaricious person.
The Dutch name is probably also the origin of German Kakerlak, Swedish kackerlacka and Danish kakerlak. Portuguese has carocha, carocho, beetle, apparently from Spanish.
The Spanish word was altered in English to cockroach by folk-etymological association with the noun cock and (perhaps) the noun roach, denoting a freshwater fish.
An American-English shortening of cockroach, the noun roach appeared in the early 19th century. The widespread adoption of this shortened form was perhaps motivated by analogy with the word pair cockchafer and chafer and with compounds of cock denoting male animals beside their uncompounded equivalents, as in cock-pheasant. It was perhaps also partly motivated by embarrassing homonymy with cock in the sense of penis; in his translation of the comedies of Aristophanes (1837), the English-born American entomologist Benjamin Dann Walsh (1808-69) wrote the following footnote:
“Cock-roaches” in the United States, as we are told by one of the numerous English travellers through that country, are always called “roaches” by the fair sex, for the sake of euphony.
Besides cancrelat, French has the word cafard. Originally, in the early 16th century, this noun denoted a Pharisee (a person whose piety is false), hence in the mid-16th century a hypocrite. It is from Arabic kāfir, infidel, impious wretch, one who does not recognise the blessings of God, from the verb kafara, to cover up, conceal, deny (cf. English Kaffir). The unfamiliar Arabic ending was assimilated to the French suffix -ard, forming pejorative nouns. In the mid-16th century, the name cafard was applied, by metaphor, to the cockroach, this insect being of a dark colour and avoiding light. The sense cockroach of cafard gave rise in turn to the sense melancholia, depression (French uses idées noires, literally black thoughts) in the phrase avoir le cafard, literally to have the cockroach, synonym of avoir le bourdon, literally to have the bumblebee. English borrowed cafard in this sense in the early 20th century.