Adjective
1. being neither at the beginning nor at the end in a series;
"adolescence is an awkward in-between age""in a mediate position""the middle point on a line"2. equally distant from the extremes
3. of a stage in the development of a language or literature between earlier and later stages;
"Middle English is the English language from about 1100 to 1500""Middle Gaelic"4. between an earlier and a later period of time;
"in the middle years""in his middle thirties"