To leave someone or something behind, often in a difficult situation, without intending to return. The sailors had to abandon the sinking ship to save their lives.
To give up completely a course of action, a practice, or a way of thinking. She decided to abandon her plans to travel abroad due to unforeseen circumstances.
To allow oneself to indulge in (a desire, emotion, etc.) without restraint. He abandoned himself to grief after the loss.