Sad tidings to start with: Corona, possibly, has returned (6)
I believe the answer is:
tragic
'sad' is the definition.
(similar in meaning)
'tidings to start with corona possibly has returned' is the wordplay.
'to start with' indicates taking the first letters.
'corona possibly' becomes 'cigar' (Corona is a brand of cigar).
'has returned' is a reversal indicator.
The initial letter of 'tidings' is 't'.
'cigar' reversed gives 'ragic'.
't'+'ragic'='TRAGIC'
(Other definitions for tragic that I've seen before include "Shocking" , "like King Lear" , "Grievous" , "Deeply distressing" , "Pathetic" .)