Here's what rhymes with firstborn.
born borne torn barn darn porn tarn corn worn horn warn yarn adorn morn mourn thorn shorn forborne lorn scorn sworn forlorn unborn reborn outworn stillborn lowborn waterborne forewarn lovelorn peppercorn timeworn unworn sweetcorn careworn forsworn foresworn unicorn Words that almost rhyme with firstborn
charm dorm form farm warm harm storm norm forme perform alarm forearm psalm swarm disarm deform firearm rearm underarm reform inform thunderstorm outperform preform vermiform yardarm overarm rewarm conform lukewarm fusiform nonfarm multiform schoolmarm uniform transform cruciform misinform chloroform cuneiform nonuniform don dawn bon pawn bonne john upon non drawn gone von con lawn yon hon wan baton fawn han schon spawn yawn khan sawn sonne vpon brawn prawn faun gnawn thereon salon swan yuan fagon npon operon begone chaperon chiffon hereupon pecan tenon hereon mastodon predawn autobahn outdrawn undergone withdrawn thereupon foregone positron whereon echelon exon octagon redrawn forgone overdrawn aileron amazon antiphon heptagon lasagne upsilon frogspawn methadon whereupon polygon automaton denouement pantheon hexagon paragon pentagon epsilon tarragon woebegone leprechaun neocon trimaran phenomenon lexicon marathon carillon cordovan emoticon rapprochement pantechnicon