Spooner describes river originating at range (7)
I believe the answer is:
freedom
'range' is the definition.
(thesaurus)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for freedom that I've seen before include "'. . . . . . .'s just another word for nothin' left to lose' (Kristofferson)" , "Power to act without restraint" , "Release" , "Independence" , "Liberty, civil liberty" .)