trustingly, trustfully, credulously
Собака доверчиво смотрела ему в глаза
The dog looked trustingly into his eyes.
Ребёнок доверчиво взял конфету у незнакомца
The child trustingly took the candy from the stranger.
Она доверчиво рассказала ему свой секрет
She trustingly told him her secret.
