My middle-grade novel is third person with one primary and one secondary viewpoint character. Sometimes the narrator hovers a bit more, sometimes the narrator is more in the character's head.
The narrator primarily describes things the way the character might. For example one character will refer to one of the younger children by name while the other viewpoint character calls him "that little twerp."
As these characters travel back in time and across the world, they encounter a lot of things they're not familiar with. Even things an educated adult from their time and place may not know.
Do I name them?
I don't want half the dialogue to be "oh what do you call that?" Nor do I want every description to be non-specific to their new setting. If there's an English modern version of the thing they're describing, I use that name. For example, one character talks about eating cheese that looks like feta and wearing a tunic, even though the local names are different (I'm not talking about translation here, I mean the correct names in English, which can be a loan word or not).
OTOH, I've also referred to the enormous tree in their courtyard as the terebinth tree (only when they arrive, after that it's just a big tree) and I name the cloth in use as linen, a fabric used in modern times too, but one the kids might not know.
Where is the balance between allowing the narrator to describe the scene and keeping the point of view?