Tireless rhymes with:
colorless, fatherless, featherless, featureless, humorless, leaderless, odorless, paperless, powerless, rudderless
Tireless sounds like:
tarheels, terlecki, terlizzi, thrills, trails, trails', trailways, trailways', treeless, trellis, trial's, trials, trilogy, trolleys, trulock, truluck, turlough, tutorials, twirls