Gentle rhymes with:
accidental, coincidental, compartmental, continental, dental, detrimental, developmental, elemental, environmental, experimental, fundamental, incidental, incremental, instrumental, intercontinental, intergovernmental, judgemental, judgmental, lentil, mental, monumental, nongovernmental, occidental, occidentale, oriental, ornamental, pancontinental, parental, pimental, regimental, rental, sentell, sentimental, simental, supplemental, temperamental, transcendental, transcontinental, unsentimental, yentl
Gentle sounds like:
genital, genitalia, genteel, gentile, gently, gintel, gondola, gundel, gundle