Threatening rhymes with:
battening, brightening, captaining, disheartening, enlightening, fattening, flattening, frightening, heartening, heightening, lightening, shortening, smartening, straightening, sweetening, tightening
Threatening sounds like:
tardiness, tartness, teradyne's, thirteen's, thorton's, threading, threatens, thwarting, tiredness, trading, trading's, tradings, traditions, treading, treating, triton's, trotting