Reading novels of old, one frequently runs across vocabulary rarely used these days. Congé, a French/middle English term, refers to an abrupt dismissal. Georgette Heyer uses it whenever a bored nobleman dismisses his mistress, usually with a generous parting gift. There are also less severe connotations attached to the term, such as a formal military permission to depart, or a simple leave taking.
These key sentences will place the term in context:
At the fete [the Prince Regent] gave in June 1811 to celebrate the advent of the Regency neither his legal nor his morganatic wife were invited. Mrs. Fitzherbert had already been given her congé, and the Princess of Wales was not allowed anywhere near Carlton House. – High Society, Venetia Murray, p 21
She thinks he is infatuated. but will find out his mistake and return to her,” replied old Mrs Poyntz, who was an authority of great value having been the wildest of flirts some forty years ago. “Then I dare say she will give him his congé. Meanwhile being a very proud and clever girl/ she pretends to see nothing – ignores the whole affair. Frank Leslie’s Pleasant Hours By Frank Leslie, 1879.
After some time of active service he obtained a congé and permission to travel, which carried him after some wanderings to Milan, where he staid at a friend’s chateau near the city. Harper’s New Monthly Magazine By Henry Mills Alden, 1858.
Wessex himself fought a very different war, his captaincy almost a formality; a liveried carte blanche that provided him the congé to some of the circles in which he must move. A Heart for Every Fate