Make plain, using charm abroad (5,3)
I believe the answer is:
spell out
'make plain' is the definition.
(thesaurus)
'charm abroad' is the wordplay.
'charm' becomes 'spell' (I've seen this before).
'abroad' becomes 'out' (I've seen this before).
'spell'+'out'='SPELL OUT'
'using' acts as a link.
(Other definitions for spell out that I've seen before include "writing letters?" , "Give precise details" , "Explain in detail" , "Temporary release from prison" .)