Ionizing rhymes with:
antagonizing, dehumanizing, demonizing, galvanizing, harmonizing, hellenizing, humanizing, immunizing, organizing, patronizing, reorganizing, revolutionizing, scrutinizing, synchronizing, unionizing, womanizing
Ionizing sounds like:
imagines, imaging, imagining, immunizing, inasmuch, incense, inching, incisions, incomes, incoming, ingenious, ingenuous, innocence, inocencio, insomniac, insouciance