adverb, noun, noun which may take the genitive case particle 'no'
Used to refer vaguely to something previously mentioned or understood from context, often when recounting events or instructions without repeating details. Functions adverbially or as a noun with の.
彼はしかじかの理由で遅刻したと言った。
He said he was late for such and such a reason.
しかじかの事情があって、参加できません。
Due to certain circumstances, I cannot participate.
かくかく is often paired with しかじか (as in かくかくしかじか) to mean 'this and that' or 'such and such', but しかじか alone is more common in modern Japanese.
Reduplication of 然 (shika), an old demonstrative root meaning 'that way' or 'so'. The exact historical derivation is uncertain, but the form is used in classical and modern Japanese as a placeholder for unspecified details.