What’s the difference between nightfall, dusk, and twilight? Poetry!
Entre chien et loup, literally between dog and wolf, is a poetic way of saying au crépuscule, à la tombée du jour, i.e. at dusk, at the twilight hour. It is used to describe a specific time of day, just before night, when the light is so dim you can’t distinguish a dog from a wolf. In the most basic sense, the dog represents the day while the wolf symbolizes the night.
But you can take it much further than that. The idiom also expresses that limit between the familiar versus the unknown, friend versus foe, the domestic and the wild. In that time between the dog and the wolf, we cannot always know whether we are safe or threatened. We might feel deceived by our eyes and question if we truly know what we think we know. We can feel caught somewhere between comfort and fear, what is real and unreal.
The expression was already used in Roman Antiquity with the Latin phrase "Inter canem et lupum", which itself likely derived from earlier languages - a Hebrew text from the 2nd century BC reads: "when man cannot distinguish the dog from the wolf". In French, the early written records date back the 13th century.
Je n’aime pas sortir entre chien et loup à la campagne; je ne me sens pas tranquille.
I don’t like going out at dusk in the countryside; I don't feel at ease.
Entre chien et loup, il semble que le temps s'étire, que même les oiseaux volent au ralenti.
Towards the end of the afternoon, time seems to almost stand still; even the birds appear to fly in slow motion.