Loyal, possibly, to certain union (5)
I believe the answer is:
alloy
'certain union' is the definition.
The definition and answer can be both states of affairs as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'loyal possibly' is the wordplay.
'possibly' indicates an anagram.
'loyal' with letters rearranged gives 'ALLOY'.
'to' acts as a link.
Can you help me to learn more?
(Other definitions for alloy that I've seen before include "Metals fused together" , "Mixture of two or more metals" , "Eg, pewter or brass" , "Bronze, say" , "Mixed metal" .)