Troncoso rhymes with:
moscoso, amoroso, barroso, boso, bosso, cardoso, delgrosso, delrosso, formoso, fragoso, fregoso, gaudioso, glorioso, grosso, loso, luminoso, minoso, monterosso, moscoso, mosso, osso, pedroso, peloso, prezioso, raposo, reynoso, rosso, santosuosso, toso, veloso, virtuoso
Troncoso sounds like:
tarango, tarmac, tarmacs, tarnish, tarnowski, tarrance, tarring, tearing, teetering, teheran's, teherani's, teheranis, teherans, tehran's, tehrani's, tehranis, tehrans, terence, terence's, term's, terming, terms, ternes, terns, terrains, terrance, terrence, terrones, thermco, thermos, thorn's, thornock, thorns, throng, throngs, throwing, tiramisu, tiring, torrance, torrence, torrens, torumi's, tottering, tourangeau, touring, tourneys, towering, train's, trainees, training, trains, tramco, trams, trance, tranche, tranches, trang, trans, transcisco, transco, transkei, transohio, transou, transue, transway, traumas, tremens, trench, trenches, trimac, trimas, trimming, trimmings, trims, trinka, triremes, trnka, tronic, trounce, troung, troyanos, truancy, truman's, trumka, trunk, trunks, trunzo, truong, try-ons, trying, turing, turnage, turning, turnkey, turns, tutoring, tyrannies