An atom is a mark that cannot be broken down any further. There are 138 of them, and every other word in the language is built by putting them next to each other. Set NEGATE beside SELF and you have the word for unself. Nothing is spelled out letter by letter, because there are no letters. A word is a short row of meanings, read left to right.
The line under each mark is the meaning that was recorded when the mark was made. It is worth reading rather than guessing from the name, because some of the names look like ordinary English and mean something narrower. FLUID is about time that stretches, not about water. GROUND is the word "because". Building a word from the names instead of these meanings is how a word ends up quietly wrong.