Dissipate in liquid (8)
I believe the answer is:
dissolve
'dissipate in liquid' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for dissolve that I've seen before include "So devils arrange to disappear gradually" , "Annul or end, a marriage say" , "Cut to next scene" , "Liquefy; dismiss (Parliament)" , "Put end to marriage - in water?" .)