Words That Rhyme With "Firsts" :
1 syllable:
arse, birse, burse, bursts, carse, curse, Erse, hearse, Hearst's, hirst's, Kars, marse, nurse, parse, purse, sparse, terce, terse, thyrse, verse, worse
2 syllables:
adverse, amerce, asperse, averse, coerce, converse, disburse, disperse, diverse, immerse, inverse, obverse, outbursts, perverse, rehearse, reverse, submerse, transverse