Indispensable, must be done (9)
I believe the answer is:
necessary
(Other definitions for necessary that I've seen before include "Inescapable" , "Essential, as scenery may be" , "Required to be done" , "the money?" , "Vital" .)
I believe the answer is:
necessary
(Other definitions for necessary that I've seen before include "Inescapable" , "Essential, as scenery may be" , "Required to be done" , "the money?" , "Vital" .)