Doubledecker rhymes with:
decker, dekker, baecker, becher, becker, beker, bekker, blecher, blecker, brecher, brecker, checker, decker, dekker, dequeker, ecker, fecher, haecker, hecker, hekker, klecker, necker, pecor, pekar, quebecker, recker, schaecher, secor, smrekar, specker, sprecher, stecher, stecker, strecker, swecker, trecker, wecker, wrecker, zecher