THESAURUS
firmly
adamantly, bec et ongles, bona fide, close, closely, committedly, compactly, consistently, constantly, deafeningly, decidedly, decisively, densely, determinedly, devotedly, dourly, earnestly, faithfully, fast, firm, fixedly, forcefully, forcibly, grimly, hammer and tongs, hardly, heart and soul, heartily, heavily, immovably, immutably, imperviously, implacably, impliably, impregnably, in all seriousness, in earnest, in good earnest, in good faith, inexorably, inflexibly, inseparably, intensely, intransigently, invincibly, invulnerably, ironhandedly, irreconcilably, irresistibly, like a bulldog, like a leech, loudly, loyally, lustily, mightily, obdurately, obstinately, perseveringly, persistently, powerfully, pungently, purposefully, relentlessly, resistantly, resolutely, resolvedly, responsibly, rigidly, rigorously, robustly, ruggedly, securely, seriously, sincerely, singlemindedly, solid, solidly, soundly, stalwartly, staunchly, steadfastly, steadily, sternly, stiffly, stoutly, strongly, sturdily, tenaciously, thick, thickly, tight, tightly, tooth and nail, unalterably, unbendingly, unchangeably, uncompromisingly, unregenerately, unrelentingly, unswervingly, unwaveringly, unyieldingly, vigorously, wholeheartedly, with a will, with constancy, with good faith, with total dedication