I think that's the beauty. If economy is not growing, there is no deflation. So if people are not spending, economy will be slower, deflation will be either slow, or not even there.

Deflation only occurs if money supply is fix, and economy is expanding. But it won't expand, if people are hoarding money. So to say:

Economy is growing -> deflation occurs -> people start to hoard -> deflation dissapears -> people spend again -> economy starts to grow again -> repeat