Here's what rhymes with toughening.
roughening Words that almost rhyme with toughening
doubling bubbling summoning tunneling juggling puddling ruffling bludgeoning pummeling pummelling bucketing puzzling troubling tumbling bustling bumbling bundling bungling huddling muddling scuffling shuttling suctioning buttressing funneling plummeting jumbling cudgelling junketing gunrunning fuddling stomaching summonsing functioning struggling stumbling fumbling rumbling humbling hustling mumbling coveting scuttling trumpeting guzzling nuzzling redoubling reshuffling snuggling bloodsucking muzzling muscling befuddling crumbling grumbling discomfiting coruscating encompassing malfunctioning disgruntling