Make it clear one needs a period abroad (5,3)
I believe the answer is:
spell out
'make it clear' is the definition.
(thesaurus)
'period abroad' is the wordplay.
'period' becomes 'spell' (spell can mean a period of time).
'abroad' becomes 'out' (abroad can mean away or out).
'spell'+'out'='SPELL OUT'
'one needs a' acts as a link.
This may not be correct. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for spell out that I've seen before include "writing letters?" , "Explain in detail" , "Give precise details" , "Temporary release from prison" .)