'Unfaithfully' in the Bible

And Shechaniah the son of Jehiel, of the sons of Elam, answered and said to Ezra, We have acted unfaithfully toward our God, and have taken foreign wives of the peoples of the land; yet now there is hope for Israel concerning this thing.

And Ezra the priest stood up and said to them, Ye have acted unfaithfully, and have taken foreign wives, to increase the trespass of Israel.