言う means to say, to utter, or to state. It focuses on the specific content of what is being said. It is commonly used with the particle と to report speech or to give a name to something (e.g., ~と言う - to be called ~).
That is how Fuguro works. It brings 言う back for review right before you forget it, each time a little later, until it sticks for good. You hear it spoken aloud, and you meet it again in stories you can already read. The first five levels are free.