Initially praised one excellent US writer (3)
I believe the answer is:
poe
'us writer' is the definition.
(I've seen this before)
'initially praised one excellent' is the wordplay.
'initially' suggests taking the first letters.
The initial letters of 'praised one excellent' is 'POE'.
(Other definitions for poe that I've seen before include "Edgar Allan --, US poet and author" , "Edgar Allan . . ., writer of spooky tales" , "Edgar Allan . . ., American writer of creepy stories" , "Short-story writer" , "He wrote short stories" .)