Tightening rhymes with:
brightening, enlightening, frightening, heightening, lightening, battening, brightening, captaining, disheartening, enlightening, fattening, flattening, frightening, heartening, heightening, lightening, shortening, smartening, straightening, sweetening, threatening
Tightening sounds like:
tajikistan's, tastiness, tasting, tastings, techsystems, tectonic, tectonics, testimonies, testing, thaxton's, ticketing, tightenings, tightens, tightness, toasting, touchdowns, twisting