ceaseless

Ceaseless, a.

Without pause or end; incessant.

1 other Webster entry under this spelling

Ceaseless, adv.

Without intermission or end.

Shades of meaning

Fernald has no entry of its own for ceaseless; he lists it under continual.

Where he writes about it:

A similar distinction is made between incessant and ceaseless. — from continual

The incessant discharge of firearms makes the ceaseless roar of battle. — from continual

none given