(adv.) In an observant manner.

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