Hostile Republican consumed in obsession (11)
I believe the answer is:
threatening
'hostile' is the definition.
Both the answer and definition are adjectives. Perhaps you can see a link between them that I don't see?
'republican consumed in obsession' is the wordplay.
'republican' becomes 'R' (abbreviation in US politics).
'consumed' becomes 'eaten' (similar in meaning).
'in' is an insertion indicator.
'obsession' becomes 'thing' (as in 'having a thing' for someone or something).
'r'+'eaten'='reaten'
'reaten' placed inside 'thing' is 'THREATENING'.
Can you help me to learn more?
(Other definitions for threatening that I've seen before include "giving a warning for the future" , "Minatory" , "Dangerous" , "Putting at risk" , "Scary" .)