dîner

to have your midday meal

déjeuner

In standard French you déjeuner at midday and dîner in the evening. Belgium, Switzerland, Canada and parts of France keep dîner for the midday meal, which is the older sense.

On dîne à midi pile chez mes parents, pas une minute plus tard.

We have lunch at noon on the dot at my parents', not a minute later.

From the late Latin disjejunare, to break the fast. In France the meal it named crept later over the centuries, from morning to noon to evening, and by the 19th century it meant the evening meal. Belgium, Switzerland and Quebec stopped at noon.

BelgiumSwitzerlandCanadaCongo-KinshasaHaitiHauts-de-France, Grand Est, Occitanie