Both are better literal translations, but I'm confused here because I don't really know grammar--seems like in the english sentence "out to dinner", the word "dinner" is effectively a noun, just like "restaurant"., while "cenar" is a verb. But presumably "salio a la cena" isn't grammatically correct in Spanish, and it so, you can't literally translate "the owl went out to dinner."
I think its great when Duo's perferred translation is "natural" (in spite of difficulties as reflected in the endless arguments about what it natural), but I sure wish they'd always take the literal translation when it makes sense.
The verb cenar means "to eat dinner" which can be translated as "to dine" although saying "to dine" sounds a bit archaic or formal in English (at least to my ear). As I mentioned to GarethViejoLento, the phrase salir a literally translates to "to go out to" and when accompanied by cenar, the full phrase means "to go out to dinner." Think salir a + cenar (or any of the "meal verbs") as a set phrase which really only has one translation: salir a cenar (or desayunar/almorzar/comer) should always translate to "to go out to dinner" (or breakfast/lunch/eat)
No, I'd say the more correct translation is "to go out to dinner." When you see salir a cenar (or desayunar / almorzar / comer), these words together form a set phrase that means one thing: "to go out to dinner (or breakfast / lunch / eat)". It looks as if Duo has added "the owl went out to dine" as an acceptable alternate translation, even though it's not the best or most natural translation.
It might be worthwhile, in this thread, to point out that dinner is the main meal of the day. Depending on who you are or where you live, dinner could be in the middle of the day. The evening meal is supper and is therefore equal to the Brits use of tea. I'm curious to know if Spanish makes that distinction.