An anomaly exists in the English language. (Note: all languages for that matter). This thing is to English what prime numbers are to Math. This thing is to language what a treasure map is to spectacular pirate booty.
word
The idea of “word” is the starting point of all language. Imagine a student attempting to speak a strange dialect – a dialect he’s had zero experience with. The most practical learning tool he can be taught is:
“What is the word for …”
(or its counterpart: “How do you say …”)
Both fulfill one purpose. Both make a request for word. In order for this process to take place, one must first learn the “idea” of word.
Word must pre-exist. Much like a treasure map in the quest for riches. Without the map, we wouldn’t know where or how to begin. If our student perseveres in asking, while seeking the help of native speakers, he shall soon master a new dialect.