Synonyms and related words :
amidships, average, central, core, equatorial, equidistant, halfway, heartland, hinterland, inland, inlands, inshore, interior, intermediary, intermediate, mean, medial, median, mediocre, mediterranean, medium, mesial, mezzo, mid, middle, middlemost, middling, midlands, midmost, midships, midway, nuclear, up-country