to tell a story-possibly as the main voice in a documentary; or a character who speaks to the audience in a performance
The specific meaning of narrate depends on context. For example:
"She narrated her story with tears in her eyes." — told a story
"Her diary chillingly narrates her descent into madness." — tells a story in writing
"Morgan Freeman narrated the documentary which features historic news reports and interviews." — was the voice that tells a story while tying the scenes of a documentary together
"The character who plays the Stage Director in Our Town also narrates for the audience." — when an actor in a play, movie, or other performance helps to tell the story by talking directly to the audience (breaking the imaginary barrier between the performers and the audience)
She was wretched—O so wretched—at the perception that to her companions the dairyman's story had been rather a humorous narration than otherwise; none of them but herself seemed to see the sorrow of it; to a certainty, not one knew how cruelly it touched the tender place in her experience.
3 — The Rally (68% in)
There are no more uses of "narrate" in Tess of the d'Urbervilles.