Danger which carries on (6)
I believe the answer is:
threat
'danger' is the definition.
(threat is a kind of danger)
'which carries on' is the wordplay.
'which' becomes 'that'.
'carries' is an insertion indicator.
'on' becomes 're' ('on' can be mean 'with reference to').
'that' going around 're' is 'THREAT'.
(Other definitions for threat that I've seen before include "Risk" , "Possibility of danger" , "Statement of intent to do harm" , "Statement of intention to harm" , "Declaration of intention to harm another" .)