United wearing red is logical (8)
I believe the answer is:
reasoned
'logical' is the definition.
(reasoned can mean logical or sensible)
'united wearing red' is the wordplay.
'united' becomes 'asone' (I've seen this in another clue).
'wearing' indicates putting letters inside.
'asone' put inside 'red' is 'REASONED'.
'is' is the link.
(Other definitions for reasoned that I've seen before include "Argued logically" , "Well thought out" , "Debated in calm and logical way" , "Argued, concluded" , "clear" .)