1. noun /ˈmɪdəl/
The middle of a circle is the point which has the same distance to every point of circle.
b) The part between the beginning and the end.
2. adjective /ˈmɪdəl/
a) Being in the middle or in-between; as middle point, middle name, Middle English, Middle Ages, middle weight, etc.
b) Central to.
See Also: mid-, middle-, middling
Wikipedia foundation.