fervently, zealously, devoutly, ardently, passionately
Она и́стово молилась.
She prayed fervently.
Старик истово верил в свою правоту
The old man fervently believed that he was right.
Она истово молилась перед иконой каждый вечер
Every evening, she prayed fervently before the icon.
Он истово трудился на этой работе
He worked with great dedication at this job.
WiktionaryPONSbab.laReverso
