to turn: to change the direction something faces, moves, or points
At its root this is the ordinary verb for turning. Most often it describes a person pivoting their body, especially the vivid Gospel picture of someone turning around to face and speak to another ("he turned and said"). From that plain physical core the word stretches in natural directions: turning something back to where it came from (returning it), turning a part of the body toward someone (offering the other cheek), and turning one thing into another (water into blood).
It also carries an inward, figurative sense. A person can turn in heart or allegiance, whether turning back toward an old loyalty, turning toward a new mission, or turning in the deep sense of being changed and converted. In one striking case God himself is the one who turns, meaning he turns away and withdraws.
These are not separate words but one flexible verb. English "turn" happens to bend in almost the same ways, which is why it usually translates well, though a few of its uses need a fuller phrase like "give back" or "be converted."