Threaten rhymes with:
breton, bretton, retton, baeten, betten, betton, breton, bretton, jetton, kveton, margaretten, netan, retton, sletten, tibetan, vanetten
Threaten sounds like:
tarrytown, tartan, teradyne, tetterton, thirteen, thorton, tradition, trautman, trautmann, trautwein, tretinoin, trettin, tritium, triton, trodden, trotman, trotten, troutman, troutwine, turton