fervency(n = noun.feeling) ardor, ardour, fervidness, fervor, fervour, fire - feelings of great warmth and intensity; "he spoke with great ardor"
is a kind of passion, passionateness
has particulars: zeal
Derived form adjective fervent₁

   The state of being fervent or warm; ardor; warmth of feeling or devotion; eagerness. [1913 Webster]
"When you pray, let it be with attention, with fervency, and with perseverance." [1913 Webster]

N  feeling, suffering, endurance, tolerance, sufferance, supportance, experience, response, sympathy, impression, inspiration, affection, sensation, emotion, pathos, deep sense, warmth, glow, unction, gusto, vehemence, fervor, fervency, heartiness, cordiality, earnestness, eagerness, empressement, gush, ardor, zeal, passion, enthusiasm, verve, furore, fanaticism, excitation of feeling, fullness of the heart, passion, ecstasy, blush, suffusion, flush, hectic, tingling, thrill, turn, shock, agitation, quiver, heaving, flutter, flurry, fluster, twitter, tremor, throb, throbbing, pulsation, palpitation, panting, trepidation, perturbation, ruffle, hurry of spirits, pother, stew, ferment, state of excitement, feeling, sentient, sensuous, sensorial, sensory, emotive, emotional, of feeling, with feeling, warm, quick, lively, smart, strong, sharp, acute, cutting, piercing, incisive, keen, keen as a razor, trenchant, pungent, racy, piquant, poignant, caustic, impressive, deep, profound, indelible, deep felt, home felt, heartfelt, swelling, soul-stirring, deep-mouthed, heart-expanding, electric, thrilling, rapturous, ecstatic, earnest, wistful, eager, breathless, fervent, fervid, gushing, passionate, warm-hearted, hearty, cordial, sincere, zealous, enthusiastic, glowing, ardent, burning, red-hot, fiery, flaming, boiling over, pervading, penetrating, absorbing, rabid, raving, feverish, fanatical, hysterical, impetuous, impressed with, moved with, touched with, affected with, penetrated with, seized with, imbued with, devoured by, wrought up, struck all of a heap, rapt, in a quiver, enraptured, heart and soul, from the bottom of one's heart, ab imo pectore, at heart, con amore, heartily, devoutly, over head and ears, head over heels, the heart big, the heart full, the heart swelling, the heart beating, the heart pulsating, the heart throbbing, the heart thumping, the heart beating high, the heart melting, the heart overflowing, the heart bursting, the heart breaking, the heart goes out, a heart as big as all outdoors (sympathy).