The news is bad for a porter (6)
I believe the answer is:
report
'the news' is the definition.
(report is a kind of news)
'bad for a porter' is the wordplay.
'porter' anagrams to 'REPORT'.
But, I'm unsure how the anagram is indicated.
'is' is the link.
Can you help me to learn more?
(Other definitions for report that I've seen before include "Announce; gunshot" , "Inform about the sound of thegun" , "Gunfire noise; rumour" , "Make a complaint about (someone)" , "A loud bang, or an account" .)