unquenchable (adjective)

1. In the action movie, the hero's unquenchable thirst for revenge drives the entire plot.

2. The religious leader preached about the unquenchable love and forgiveness of God.

3. Why was the math book unquenchable? Because it's full of unsolvable problems!

4. The alien creature had an unquenchable desire to conquer new planets and expand its empire.