THESAURUS
intently
absorbedly, advertently, ardently, assiduously, attentively, closely, continuously, determinedly, devotedly, devoutly, doggedly, eagerly, earnestly, engrossedly, fervently, fervidly, fixedly, heartily, heatedly, heedfully, impassionedly, intensely, interestedly, keenly, mindfully, observantly, passionately, perfervidly, preoccupiedly, raptly, regardfully, seriously, sharply, sincerely, steadfastly, steadily, studiously, unflinchingly, unremittingly, vehemently, with attention, with interest, with rapt attention, with undivided attention, without distraction, zealously