v.1. To place something to the rear of something or someone: I put the wires behind the bookcase, where no one can see them.
2. To provide something to someone or something as a means of support or assistance: The corporation put one million dollars behind the reconstruction project.
3. To consciously stop worrying or thinking about some unpleasant experience: I'm glad you put those bad days behind you and finished your studies.
4. To place someone in some lower or less advanced grade or class, especially due to inadequate performance: I couldn't pass all the required tests, so they had to put me behind with the beginners.