Détente is a politics word we kept from French, spelling and all. It means a time when two sides who have been tense — usually countries — start to loosen that tightness. They may talk more, threaten less, sign smaller deals. It is not the same as peace, and it is not a full friendship; the old problems are often still there. The famous use is the 1970s easing between the United States and the Soviet Union, but people also use it for any cooling of a freeze between rivals. Newspapers sometimes stretch it to office politics or a family row; that is looser than the core, country-to-country sense. Though actually, even then the picture still holds: the strain eases, nobody has become close. In English we usually keep a French-ish sound, a bit like “day-tahnt.”