bulk

plurality

maximum, most

abundance, heap, loads, lot, much, oodles, plenty, profusion, reams, scads, wealth

majority

aggregate, amount, entirety, quantum, sum, sum total, total, totality, whole

bottom, essence, essentiality, marrow, meat, nature, pith, quintessence, root, soul, stuff, substance

center, heart, hub, kernel, middle, nucleus, nut, seat

affair, argument, burden, crux, focus, gist, nub, pitch, point, purport

matter, motif, subject, text, theme, topic

area

capaciousness, commodiousness, roominess, spaciousness

ampleness, amplitude, bigness, bulkiness, enormousness, heftiness, hugeness, immenseness, immensity, largeness, mass, massiveness, monstrousness, stupendousness, tremendousness, vastness, volume, voluminousness