Something is behind you if you cannot see it - your back is facing it rather than your front. The tiger in the picture is behind a tree.
Binding is a way of holding two or more things together, usually by tying or wrapping. Book pages are bound together down one edge to form a book.
A person or animal is blind if they cannot see. People who are blind can still live very full lives. They can read books written in braille and can travel around with the help of a white cane or a seeing eye dog.
You find something if you simply stumble upon it by chance, or you are actively looking for it until you find it. The little girl in the picture is looking for shells.
You grind something by breaking parts of it off with friction. Metal or wood can be ground down by running a very rough surface over it, such as a grinding disc or sandpaper. Grinding will gradually change the shape of the thing being ground as the outer layer is removed. You grind herbs and spices in a mortar and pestle by crushing them against the inside of the bowl.
The hind parts of something are at the back or rear. In animals, you might describe them as having hind legs or hindquarters.
The rind of a fruit is the hard outer layer that you can't eat. Fruits like watermelon and oranges have rinds.