Narrower rhymes with:
borrower, beerbower, boomhower, borrower, burrower, deboer, denboer, follower, heyboer, isenhower, krakower, lawnmower, mumpower, shallower, slothower, spainhower, theatergoer, widower, yellower
Narrower sounds like:
nair, naira, namara, namer, nara, naro, narrow, nary, nauer, nayyar, ne'er, near, nearer, neary, neer, neher, nehru, neier, neimeyer, neira, nemer, nemir, neri, nerio, nero, neuer, neumaier, neumayer, neumeier, neumeyer, neuner, neuro, neurohr, newer, newmeyer, newmyer, neyer, niemeier, niemeyer, nier, nimmer, niner, nir, niro, nohr, noir, nomura, nor, nora, norah, norrie, norry, norway, nowhere, numeiri, nunnery, nur, nurr, nurre, nyerere, nyeri