Here's what rhymes with slength.
Words that almost rhyme with slength
nth lens tenth ens sense hence dense thence whence fence stems tense tens cleanse gems hens pence pens theorems dens gens glens fens harems hems immense offence offense defence defense expense intense commence dispense incense suspense pretense morphemes halfpence condemns condense sixpence recommence twopence recompense commonsense frankincense length death health strength wealth breath depth breadth stealth neath twelfth shibboleth commonwealth