Inflammation coming in worst yet (4)
I believe the answer is:
stye
'inflammation' is the definition.
(I've seen this before)
'coming in worst yet' is the wordplay.
'coming in' indicates the answer is hidden within the clue.
'STYE' is hidden in the letters of 'worst yet'.
(Other definitions for stye that I've seen before include "swelling by organ" , "Inflammation around the eye" , "Eyelid affliction" , "Eye blemish" , "makes viewer sore" .)