Is this specific to Southern Vietnam (as opposed to do an?) I wish that Duolingo would specify stuff that's specific to Southern Vietnam somehow
What does thức mean in this context?
"thức" has some meanings: mood, to stay up, to stay awake,... But in this context, you cannot divide it into two parts "thức" and "ăn", "thức ăn" is a compound noun. "Thức ăn" means "food" (the general) and means "the food" (the specific)
It marks food or even clothing. (e.g. thức ăn, thức mặc). The general definition is any raw or cooked plants or meat. Đồ ăn can mean food and thực phẩm means food products.