Horizontal rhymes with:
consonantal, periodontal, accidental, antal, antle, bantle, cantle, chantal, coincidental, compartmental, consonantal, continental, dental, detrimental, developmental, dismantle, elemental, environmental, experimental, fantle, frontal, fundamental, gentle, governmental, gruntal, incidental, incremental, instrumental, intercontinental, intergovernmental, judgemental, judgmental, kantle, lentil, lintel, mantel, mantle, mental, monumental, nongovernmental, occidental, occidentale, oriental, ornamental, pancontinental, pantle, parental, periodontal, pimental, pimentel, prefrontal, quintal, regimental, rental, sacramental, sentell, sentimental, simental, supplemental, temperamental, transcendental, transcontinental, unsentimental, wintle, yentl