Friend finishes one last letter, lovingly, emptily, bewilderedly (7)

'bewilderedly' is the definition.
Both the answer and definition are adverbs. Maybe they are linked in a way I don't understand?

'friend finishes one last letter lovingly emptily' is the wordplay.
'finishes' says to take the final letters (I've seen 'finish of' mean this).
'one' becomes 'a' (a thing is one thing).
'last letter' becomes 'zed' (in the alphabet).
'emptily' suggests removing the centre (the word is emptied of its middle letters).
'lovingly' with its middle taken out is 'ly'.
The final letter of 'friend' is 'd'.
'd'+'a'+'zed'+'ly'='DAZEDLY'

Can you help me to learn more?