This is the 2448th most frequent Japanese word.
不可欠
Indispensable; essential.
This use of '不可欠' highlights an imperative quality required for achievement.
コミュニケーション能力は成功するために不可欠です。
Communication skills are indispensable for success.
Here, '不可欠' conveys the idea of being crucial and indispensable.
技術革新は現代社会の発展に不可欠です。
Technological innovation is essential for the development of modern society.
In this sentence, '不可欠' describes health as a necessary and foundational aspect.