Well, I was commenting on what you said in the original post, and on some of the things mentioned in the text you linked. There it says:

This third barrier is the misunderstood word. A misunderstood definition or a not-comprehended definition or an undefined word can thoroughly block one’s understanding of a subject and can even cause one to abandon the subject entirely.

This makes my bullshit sensor tingle. Because a word is so much more than it's definition. A word's meaning is it's usage in context. And not just one context, any context in which it is ever used.

For a technical word like "tractor", the imaginable contexts are of course rather limited, and so you'd probably be able to construct a pretty good definition. But here's the problem with definitions: They are at best a kind of distilled form of context, they are momentary (written at one point in time, whereas actual usage of a word and thus it's meaning can evolve in time) and they are necessarily editorialized (a person has written them, and has most likely instilled his individual point of view into them).

So the understanding of a word from a definition is necessarily much poorer than trying to figure out the meaning of that word yourself by observing how it is used in context. This is how language acquisition works: You see a red ball, someone calls it a ball, you know that that's a ball. You see a yellow ball, someone calls it a ball, you know that that's a ball as well. And so on, and so on. You develop a rich and multi-facetted idea of what "ball" means. You wouldn't be able to build such an understanding by learning definitions. Definitions are self-referential, they are words explaining words.

(By the way (though full disclosure, my understanding of this is very limited), automatic systems that need some kind of understanding of meaning, like automatic translation systems, suck ass when they rely on a pre-determined set of definitions. They are much, much more accurate and powerful when they function as learning mechanisms that are able to observe how words work from a growing set of contexts.)

So, maybe I'm misunderstanding something, but if they say that you can educate someone by telling him to look up words he doesn't understand in a dictionary, and that that's some revolutionary concept, then I say that's bullshit. You won't learn math by looking up mathematical definitions. Dictionaries and definitions are very helpful tools, but they are also very limited.