IPA: /ˈθæŋkfəl.i/
KK: /θæŋkfəli/
In a way that shows gratitude or appreciation.
Thankfully, the rain stopped just in time for the picnic.
Thankfully → It is formed from "thank" (from Old English *þanc*, meaning gratitude or thanks) and "-fully" (meaning full of). The word "thankfully" means full of gratitude or expressing thanks.
Think of feeling 'full of gratitude' when you say 'thankfully' — it connects the idea of being thankful with the suffix that means 'full of'.