不ふ可か欠けつ

ふ

か

け

つ

Common wordJLPTN2Freq.FrequencyTop 10,000

Meanings

Used for something that is absolutely necessary and cannot be done without. Often appears in formal, business, or academic contexts.

Related words

必ひつ要ようN4
必要 is the common, everyday word for 'necessary', while 不可欠 is stronger and more formal, emphasizing that something absolutely cannot be omitted.
必ひっ須すN1
必須 describes a mandatory requirement or prerequisite, whereas 不可欠 stresses that a thing is irreplaceable and cannot be done without.
肝かん要よう
肝要 means 'of vital importance' with a slightly literary tone, while 不可欠 specifically means 'cannot be dispensed with'.
なくてはならない
不可欠 is a formal, written Sino-Japanese adjective for 'indispensable', while 無くてはならない is a more colloquial, everyday phrase with the same meaning.
マスト
不可欠 stresses that something is indispensable in a somewhat formal register, while マスト is a light, casual way to say the same thing.

Don't confuse with

不ふ可か能のうN3
不可能 (impossible) and 不可欠 (indispensable) share the 不可 prefix but describe unrelated concepts—one is about feasibility, the other about necessity.
不ふ可か解かいN1
不可欠 shares the 不可 prefix with 不可解 but means 'indispensable', a completely unrelated meaning to 不可解's 'incomprehensible'.
不ふ可か分ぶん
不可分 means 'indivisible/inseparable' (cannot be split apart), while 不可欠 means 'indispensable/essential' (cannot be done without); learners often confuse them because both start with 不可.