Cabin crew should be able to demystify any items that you aren't aware of. People with allergies always have to be careful, even if they think they understand what a menu item is offering them (for example, a curry may be offered on the menu, but it may contain nuts).
That said, it's been very rare that I haven't seen something on the menu that I'm not able to guess or have no idea. A lot of flowery language crowding up the item is quite often where the product comes from and adds very little to understanding the item you are getting. The other kind of thing that may not be understood is a particular kind of general item, e.g. some people may not know that halibut is a fish.
Reminds me of going to non-English speaking countries and translating some menu items, then finding that the literal translation is just a name and gives no idea of what the dish is.