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