Answer: necessary

AnswerCrossword Clue
NECESSARY

Of vital importance

NECESSARY

More of the quip

NECESSARY

Not an option

NECESSARY
Requisite
NECESSARY
Not optional
NECESSARYIndispensable.
NECESSARYMandatory.
NECESSARYKind of evil
NECESSARYEssential
NECESSARYCalled for