Jillions rhymes with:
billions, brazilians, civilians, hillians, millions, pavilions, reptilians, trillions, zillions, australians, battalions, billions, brazilians, civilians, hillians, italians, medallions, millions, pavilions, rebellion's, rebellions, reptilians, scallions, somalians, stallions, trillions, zillions
Jillions sounds like:
jaglom's, jailing, jelinek, jelinski, jiggling, jocylan's, jollying, joycelyn's, juggling