Mulling vs Dulling - What's the difference?

As verbs the difference between mulling and dulling

is that mulling is while dulling is .

is the act of one who mulls or thinks over something.

(head)

(en noun)

The act of one who mulls or thinks over something.

* 2001 , Charles Stickney, World Enough: Travel Memoirs (page 333)

My mullings over where to go with my life, and now also where to go after Phuket island, incorporated what I saw in my everyday walks

(head)