I think I might have this. Lexical-gustatory synesthesia. Certain words evoke vivid tastes. E.g. "frosty" tastes of hot buttery croissants and "good" tastes of cold strawberry yoghurt. "Yoghurt" itself has a sour lemon-like taste. I can think, hear, or read the words and will taste them. "Hungary" tastes of buttery fried potatoes.
The only bad part is if I'm hungry when I'm in the middle of class, the teacher's talking, I'm tasting words and all I can think is, "Food, food, food. Hungry, hungry, hungry."