Crucial

9 clues
Key
Acute
Decisive
Determining
Very important
Of the essence
Extremely important
Of great importance
Like the seventh series game
Similar answers:
Abcrunch
Abcrunches
Accrual
Accruals
Accrue
Accrueacrew
Accrued
Accruedbenefits
Accruedinterest
Accruedoil
Accruedsnterest
Accruer
Accrues
Accruing
Aclockworkorangecrush
Acrumb
Acrushofteenagers
Acrushofwrestlers
Afatesocruel
Anacruses