The word detach originates from the Old French desattachier, meaning “to unfasten, disunite,” which is derived from the prefix des- (indicating reversal or removal) and attachier (“to attach”). The root attachier itself comes from the Vulgar Latin attachicare, which is related to fastening or joining. The modern sense of the term, “to separate” or “to disconnect,” emerged in English around the early 17th century.