To move about without a fixed course, aim, or goal. He likes to wander through the city streets, exploring new neighborhoods.
To go astray morally; err. She began to wander from the values she was taught as a child.
To lose clarity or coherence of thought or expression. During the lecture, his mind began to wander, and he missed important points.
To move around or traverse (a place) in a leisurely, casual, or aimless manner. During his vacation, he wandered the cobblestone streets of the old city.