indispensable

英 [ɪndɪ'spensəb(ə)l] 美['ɪndɪ'spɛnsəbl]

• adj. 不可缺少的；绝对必要的；责无旁贷的
• n. 不可缺少之物；必不可少的人

1. not to be dispensed with; essential;

"foods indispensable to good nutrition"

2. absolutely necessary; vitally necessary;

"essential tools and materials"

"funds essential to the completion of the project"

"an indispensable worker"

3. unavoidable;

"the routine but indispensable ceremonies of state"