由ゆ々ゆしき

Meanings

noun-modifying (irregular)

Prenominal form of 由々しい, used only before nouns. Describes a situation, matter, or problem that is very serious and cannot be ignored. Often used in formal or written contexts.

Kanji

由wherefore, a reason

Related words

由ゆ々ゆしい
由々しい is the dictionary form (終止形) and can be used predicatively (e.g., 問題は由々しい), while 由々しき is the prenominal form used only before nouns.
深しん刻こく
深刻 is a more common and neutral word for 'serious' or 'grave', while 由々しき is more formal and emphatic, often implying a sense of alarm or urgency.

Written forms

由ゆ々ゆしき
Standard kanji spelling using the iteration mark 々. This is the most common written form.
由ゆ由ゆしき
Full kanji spelling without the iteration mark; rarely used in modern writing.

Etymology

The prenominal form of 由々しい (yuyushii), an adjective meaning 'grave' or 'serious'. The kanji 由 means 'reason' or 'cause', but the exact derivation of the word is uncertain. The repetition of the kanji (由々) intensifies the meaning.