What does the policy rate mean?

In the context of expansionary / restrictive fiscal policy, what does it mean by a decrease in the policy rate?

And just to confirm, does more gov spending = expansionary fiscal policy?

In the US, the policy rate is the Fed funds rate. Similarly in other countries.

Yes: more government spending is expansionary fiscal policy.

Thanks, and what does it mean to “monetize debt through an accommodative monetary policy”?

Print mo money!