I didn’t actually downvote, but I do object to your characterisation of this as misleading. People aren’t labelling their products with the intent that the people buying it believe they’re eating meat.
Those labels are designed to communicate what sort of thing you can do with it. If you label something “burger”, for example, everyone will understand at a glance what they’re looking at, and that you might like to put it between two buns with some lettuce. It will also catch the attention of people who are looking to make burgers, but might not have considered non-meat options.
Also, common usage of words like “burger” aren’t limited to anything specific. People talk about “chicken burger” or “turkey burger” all the time, for example, and nobody accuses them of trying to trick people into eating chicken. Why not a “lentil burger” as well?
You were asking for definitions, and I responded by pointing out that they definitely exist. The fact that you or I don’t personally come from a background which values those definitions doesn’t mean they don’t exist, or that other people don’t use them.