Instead of a menu, just a sidebar text?

Is it possible to be able to hover instead of a menu, just a sidebar text?
And how;
i tried many ways but failed.

And how do you "hover" on a smartphone ?

I do not know.

I thought instead of a menu coming out, a description text coming out

There a menu appears like: Home, about us, etc
to output only one description, one text only

Draw a picture, show what you mean

Here in the first one, on the top right, it has a round button, you press it and it brings up the second image from the bottom, then you press the: About and it brings up another screen where you write the text.
Does the text instead of coming out on another screen, come out instead of the About what the second screen is showing?

Just use a button to display text in a label ?