Perfervid

The candidate made perfervid promises of reform.

Source: tatoeba (10649932)

Manders — perfervid — 'hell'-ing excitedly (was there no one left on earth to convert but me?), quoting over a century from Marx and Nietzsche to Lenin, Lloyd George, and Eden, and on to Vessant and Mundaine and himself...

Source: wiktionary

In this case he saw himself sitting beside the breathing slender figure of Pia like someone in an old engraving – a beastly old Rembrandt exhaling the perfervid gloom of Protestantism and a diet of turnips.

Source: wiktionary

Ah threw mahself down the porch steps and fell to mah knees in the middle of the yard, wringing mah hands and beating at the sky and wailing and reeling in the red dust and petitioning the almighty with perfervid prayer.

Source: wiktionary