What is another word for without ever ceasing?

Here are some words that could be used to convey the idea of "without ever ceasing":

Formal:

* Continuously

* Incessantly

* Perpetually

* Constantly

* Unceasingly

* Relentlessly

* Indefatigably

Informal:

* Non-stop

* Never-ending

* Forever

* Always

* Without pause

The best word to use will depend on the context and the desired tone.