key - most essential, most important, main, chief thing, crucial influential⏎
maintain - keep, continue, record, check, support sustain provide⏎
economic - profitable, cost-effective, viable, financial, commercial, trading⏎
mainstream - usual, normal, main (part), tendency, mass⏎
interim - lull, Short-term, not permanent⏎
ethic - moral, principle⏎
expert - ace, skilled, proficient⏎
flood - deluge, numerous, many⏎
handle - deal with, manage, be responsible for, organise, organize⏎
gimmick - trick, novelty, contrivance⏎