Geronimo circumspect over religion
I believe the answer is:
war cry
'geronimo' is the definition.
(thesaurus)
'circumspect over religion' is the wordplay.
'circumspect' becomes 'wary' (I've seen this before).
'over' is an insertion indicator.
'religion' becomes 'cr' (I can't justify this - if you can you should give a lot more credence to this answer).
'wary' enclosing 'cr' is 'WAR-CRY'.
(Other definitions for war cry that I've seen before include "Christian slogan" , "rallying call" , "Word shouted in attach on enemy" , "Religious publication" , "slogan, for example" .)