Release at no charge (4)
I believe the answer is:
free
I believe this is a double definition.
'release' is the first definition.
(I know that release can be written as free)
'at no charge' is the second definition.
(I've seen this in another clue)
(Other definitions for free that I've seen before include "Unrestricted" , "Untie" , "Available - for love" , "with no toll demanded?" , "As cheap as can be!" .)