échoir

A formal, mostly written/legal verb meaning to fall due (une dette échoit à telle date) or to fall to someone as their lot or responsibility (la tâche lui échut) — irregular and largely confined to administrative, legal, and literary registers.

• Le loyer échoit le premier de chaque mois. — The rent falls due on the first of each month.
• Cette responsabilité lui échoit naturellement en tant qu'aîné. — This responsibility falls to him naturally as the eldest.
• Le délai de paiement échoit dans trois semaines. — The payment deadline falls due in three weeks.

Highly irregular and rarely used in speech — most learners will only meet it in the past participle échu (as in la date échue) or in fixed legal phrasing, not everyday conjugated forms.

Often confused with revenir.