THESAURUS
Midriff
abdomen, abomasum, barrier, bay window, beerbelly, belly, brattice, breadbasket, buffer, buffer state, bulkhead, bumper, center, cloison, collision mat, core, craw, crop, cushion, diameter, diaphragm, dissepiment, dividing line, dividing wall, division, embonpoint, equator, fender, first stomach, gizzard, gullet, gut, heart, honeycomb stomach, interior, interseptum, kernel, kishkes, manyplies, mat, maw, mean, median, middle, midmost, midsection, midst, nucleus, omasum, pad, panel, paries, partition, party wall, paunch, pot, potbelly, potgut, property line, psalterium, pusgut, rennet bag, reticulum, rumen, second stomach, separation, septulum, septum, shock pad, spare tire, stomach, swagbelly, thick, thick of things, third stomach, tum-tum, tummy, underbelly, ventripotence, waist, waistline, wall, zone
ROGET THESAURUS
Midriff
Middle
N
middle, midst, mediety, mean, medium, middle term, center &c, mid-course, mezzo termine, juste milieu, halfway house, nave, navel, omphalos, nucleus, nucleolus, equidistance, bisection, half distance, equator, diaphragm, midriff, intermediate, middle, medial, mesial, mean, mid, median, average, middlemost, midmost, mediate, intermediate, equidistant, central, mediterranean, equatorial, homocentric, in the middle, midway, halfway, midships, amidships, in medias res.
Interposition
N
interposition, interjacence, intercurrence, intervenience, interlocation, interdigitation, interjection, interpolation, interlineation, interspersion, intercalation, interpenetration, permeation, infiltration, intervention, interference, intrusion, obtrusion, insinuation, insertion, dovetailing, embolism, intermediary, intermedium, go between, bodkin, intruder, interloper, parenthesis, episode, flyleaf, partition, septum, diaphragm, midriff, dissepiment, party wall, panel, room divider, halfway house, interjacent, intercurrent, intervenient, intervening, intermediate, intermediary, intercalary, interstitial, embolismal, parenthetical, episodic, mediterranean, intrusive, embosomed, merged, between, betwixt, twixt, among, amongst, amid, amidst, mid, midst, in the thick of, betwixt and between, sandwich-wise, parenthetically, obiter dictum.