Merriweather rhymes with:
weather, whether, altogether, birdfeather, feather, get-together, grether, heather, leather, nether, raether, sether, tether, together, weather, whether
Merriweather sounds like:
marauder, marder, marter, martire, martyr, martyre, meridor, meritor, meriweather, meriwether, merriwether, moratoria, mortar, mortara, morter, mortier, mortuary, muratore, murder, murderer