Free water (6)
I believe the answer is:
spring
I believe this clue is a double definition.
'free' is the first definition.
(thesaurus)
'water' is the second definition.
(spring water is a kind of water)
(Other definitions for spring that I've seen before include "May, perhaps - bound" , "Season of growth" , "rise" , "Suddenly reveal" , "Resilient device" .)