Middleweight rhymes with:
actuate, antiquate, braithwaite, counterweight, cowperthwaite, deadweight, featherweight, fluctuate, garthwaite, goldthwaite, heavyweight, hundredweight, menstruate, paperweight, perpetuate, underweight, welterweight
Middleweight sounds like:
medalist, mittelstadt, mittelstaedt, mittelsteadt