Terseness rhymes with:
callousness, carelessness, cautiousness, consciousness, contagiousness, contentiousness, dangerousness, disingenuousness, fractiousness, graciousness, hellaciousness, helplessness, hoarseness, homelessness, hopelessness, joblessness, lawlessness, lessness, nervousness, niceness, outrageousness, pompousness, powerlessness, rebelliousness, recklessness, restlessness, righteousness, ruthlessness, seriousness, surfaceness, weightlessness
Terseness sounds like:
tarzan's, terrorizing, theorizing, thoroughness, thrashing, torching, tracing, tracking, tragicomic, trajan's, trashing, tregoning, trekking, tricking, trojanowski, trojans, trucking, trzcinski