To change a made thing after it is made. Editing improves and quietly rewrites the record of what was first said.
Latin editus, past participle of edere (to give out, publish), ex- (out) plus dare (to give); a made thing given out again in changed form.
Its root is a publishing, not a correcting: edere meant to give a thing out into the world, and the word only later narrowed to the changing that happens before that giving. To edit is still, underneath, an act of releasing something; the changing is just what happens on the way out the door.