Impetuous rhymes with:
incestuous, sumptuous, unctuous, assiduous, fatuous, incestuous, inconspicuous, marquess, presumptuous, promiscuous, sensuous, sinuous, sumptuous, tenuous, tortuous, unambiguous, unctuous, voluptuous
Impetuous sounds like:
imbeds, impedes, impetus, infatuates, infotech, inhabits, inhibits, innovates, inputs, invades, invidious, invitees, invites