Meaning of Back-up
Unknown / অজানা / अज्ञात
the rear part of the human body, extending from the neck to the lower end of the spine.
the part of the body of animals corresponding to the human back.
the rear portion of any part of the body: the back of the head.
the whole body, with reference to clothing: the clothes on his back.
ability for labor; effort; endurance: He put his back into the task.