G0198–ἀκριβόω–akriboō

Then Herod privily called the Wise-men, and learned of them exactly what time the star appeared.

ἠκρίβωσεν ēkribōsen “inquired exactly”

Then Herod, when he saw that he was mocked of the Wise-men, was exceeding wroth, and sent forth, and slew all the male children that were in Bethlehem, and in all the borders thereof, from two years old and under, according to the time which he had exactly learned of the Wise-men.

ἠκρίβωσεν ēkribōsen “he had ascertained”