The term 'tour-de-force' is a direct borrowing from French, entering English in the early 19th century. Literally meaning "feat of strength," it originally described a masterful or ingenious act in fields like engineering or the arts. The logic of the phrase lies in the metaphorical use of physical strength ('force') to represent exceptional skill, and a 'tour' as a remarkable turn or display of that ability. Over time, its usage broadened to describe any brilliantly executed and impressive achievement, from a literary work to a strategic maneuver, while retaining its core sense of a demonstration of supreme mastery.

This is a loan phrase from French. It is not segmented into English morphemes. The phrase is composed of the French words 'tour' (turn, feat, trick), 'de' (of), and 'force' (strength, power).