The word 'staple' can be used in various forms and you can use the word as a noun, verb and as an adjective. As an adjective the word can be used only before noun and the meaning it conveys is that of something that is basic or the most important part of something. The sentence that can help you to understand the word in this context is following: Rice is used as the staple food in most of the states of India.
When you are using the word as a noun it conveys the idea of a small piece of metallic wire that is used in the device stapler that is used to keep papers intact.
When you are using the word as a verb it conveys almost the same idea as that of as a noun and it conveys the phenomenon of attaching something with some other thing with the help of a stapler.
When you are using the word as a noun it conveys the idea of a small piece of metallic wire that is used in the device stapler that is used to keep papers intact.
When you are using the word as a verb it conveys almost the same idea as that of as a noun and it conveys the phenomenon of attaching something with some other thing with the help of a stapler.