Celebrated Irish author said to have florid coat (8)
I believe the answer is:
rejoiced
'celebrated' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
(Other definitions for rejoiced that I've seen before include "Celebrated" , "Was glad" , "Felt great elation" , "Felt great joy" , "Exulted, made merry" .)