Another word for covertly

As he maneuvered the truck through muddy ruts in the drive, she covertly studied his profile.

She covertly accepted the copied transcriptions of the young woman's notebook that Cynthia presented to her.

The Amatola mountains were stormed; and the paramount chief Kreli, who all along covertly assisted the Gaikas, was severely punished.

It was one thing to covertly admire Alex, but quite another to stand here discussing him as though he were high dollar merchandise at a low bid auction... and why was Katie so concerned?

In the Labyrinth (dedicated to Queen Elizabeth of England), a discussion of the freedom of the will, he covertly assailed the Calvinistic doctrine of predestination, and showed that his views were tinged with Socinianism.