noiselessly

This was bone-chilling, to be approached so noiselessly by a winged assassin.

Cell doors shut noiselessly, with the silence only broken when guards use clacking devices or banged metal pipes to warn colleagues that they were escorting a suspect to avoid meeting others.

He was not the dangerous one, the girl knew, but his mate who padded noiselessly through the trees.

The next day, I enter the music room noiselessly.

Almost as if on cue, a great blue heron glided past the group noiselessly, creating barely a ripple in the mirror-like waters.