あどけない の訳語→ boyish childish childlike endearingly innocence inviting juvenile little-girl
さりげなく の訳語→ absently careless carelessly casual casually casualness covert covertly delicately discreet discreetly effortlessly everyday inconspicuous matter-of-factly nonchalantly restrained simply unobtrusively unselfconsciously vague
なにげなく の訳語→ inadvertently indifferently lightly
屈託なく の訳語→ broadly cheerfully happily light-hearted
素直に の訳語→ decent dutifully easily genuinely gracefully honestly meekly passively serious straight straightforward unaffectedly