Synonyms for Middle (same or very similar meaning)
WordNet sense 1 (an area that is approximately central within some larger region):
center, eye, heart, centre
WordNet sense 2 (the middle area of the human torso (usually in front)):
midriff, midsection
WordNet sense 3 (being neither at the beginning nor at the end in a series):
in-between, mediate
WordNet sense 4 (lying between two extremes in time or space or degree):
intermediate, intermediate
WordNet sense 5 (used in combination to denote the middle):
mid
WordNet sense 6 (occurring or falling between events or points in time):
intervening
WordNet sense 7 (equally distant from the extremes):
halfway, midway
WordNet sense 8 (in or near a center or constituting a center; the inner area):
central
From the ODE community, based on WordNet
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