Current unwelcome visitor camped in compound (8)
I believe the answer is:
pandemic
'current' is the definition.
(thesaurus)
'camped in compound' is the wordplay.
'compound' indicates an anagram.
'camped'+'in'='campedin'
'campedin' with letters rearranged gives 'PANDEMIC'.
'unwelcome visitor' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for pandemic that I've seen before include "Denim cap (anag.)" , "(Of a disease) affecting a wide area" , "Damn epic about world-wide disease" , "Very widespread outbreak of a disease" , "serious outbreak" .)