Furthers rhymes with:
another's, bathers, bellwethers, birdfeather's, birdfeathers, bothers, brother's, brothers, brothers', carithers, carothers, carrithers, carrothers, carruthers, caruthers, cather's, cathers, crothers, dithers, druthers, father's, fathers, feathers, flathers, forefathers, gathers, get-togethers, gethers, godfather's, godfathers, godmothers, grandfather's, grandfathers, grandmother's, grandmothers, heather's, heathers, lathers, leathers, mathers, mother's, mothers, nethers, other's, others, others', rather's, slathers, smathers, smethers, smithers, smothers, southers, strothers, struthers, suthers, tethers, togethers, weather's, weathers, withers, zithers
Furthers sounds like:
fortier's, fortress, fortresses, forwarders, frederic, frederica, frederick, frederick's, fredericka, fredericks, frederico, frederika, fredric, fredrich, fredrick, fredricks, fridrich, friederich, friederike, friedrich, friedrichs, friedrick