rock-fast

But rock-fast as any democratic magistrate may be, public opinion must and does influence him.

The New York Times Current History of the European War, Vol. 1, January 9, 1915 What Americans Say to Europe Various

But as the shoulders of the pass were very steep on the other side, our men could not surround the enemy or attack them in the rear; and as there was not sufficient cover for them to go down the slope without great loss, in order to drive the enemy by force from their positions, the burghers remained 'rock-fast' in their positions, and made no progress at all.

On Commando Dietlof Van Warmelo 1919

The land and its animal life was unknown, the hard frozen, almost rock-fast and yet continually moving ice-covering, with which the sea was bound, was something quite novel, as also were the effects which long continued and severe cold exerts on animate and inanimate objects.

The Voyage of the Vega round Asia and Europe, Volume I and Volume II Alexander Leslie 1866

But the drift-ice round about us lay so rock-fast, that I could already take solar altitudes from the deck of the vessel with a mercurial horizon.

The Voyage of the Vega round Asia and Europe, Volume I and Volume II Alexander Leslie 1866