mid·dle 
(mĭdl)
(mĭdl)adj.
1. Equally distant from extremes or limits; central: the middle point on a line.
2. Being at neither one extreme nor the other, as of a sequence or scale; intermediate: the middle decades of the century.
3. Middle
a. Of or relating to a division of geologic time between an earlier and a later division: the Middle Paleozoic.
b. Of or relating to a stage in the development of a language or literature between earlier and later stages: Middle Swedish.
4. Grammar Of, relating to, or being a verb form or voice in which the subject both performs and is affected by the action specified.
n.
1. An area or a point equidistant between extremes; a center: the middle of a circle.
2. Something intermediate between extremes: the middle of the story.
3. The middle part of the human body; the waist.
4. Logic A middle term.
5. Grammar
a. The middle voice.
b. A verb form in the middle voice.
tr.v. mid·dled, mid·dling, mid·dles
Idiom: 1. To place in the middle.
2. Nautical To fold in the middle: middle the sail.
in the middle
1. In a difficult situation: caught in the middle of a controversy.
2. Engaged in doing something: I'm in the middle of making dinner.
[Middle English middel, from Old English; see medhyo- in the Appendix of Indo-European roots.]