Disappear; evaporate (6)
I believe the answer is:
vanish
I believe this clue is a double definition.
'disappear' is the first definition.
(I know that disappear can be written as vanish)
'evaporate' is the second definition.
(I know that evaporate can be written as vanish)
(Other definitions for vanish that I've seen before include "Become invisible" , "Cease to exist" , "Go missing" , "Evanesce" , "make go" .)