What rhymes with sixteen?

Well nothing rhymes perfectly, but you could use two Words (hate/fate/date, etc combined with mean/green/scene etc). If you really want to stretch the limits (which I don't recommend in rhyming), you could use "dating." ... If you say it correctly, it can rhyme with eighteen.

teen

80 rhymes with 18
lima bean, clean, mean, teen, wolverine, aquamarine, machine, vaccine, demean, queen, spleen, obscene, etc.