much more; let alone; not to mention
Formal, somewhat literary adverb used to emphasize that if something is true for a lesser case, it is even more true for a greater case. Often follows a negative statement or a rhetorical question, and is typically paired with ～さえ or ～すら. In modern Japanese, ましてや is more common in everyday speech.
It's difficult even for adults, let alone children.
He can't even do simple calculations, much less solve complex equations.
Usually written in kana; the kanji forms 況んや, 況や, and 况や are rare and mainly found in older or literary texts.
Rare kanji spelling without explicit ん.
Rare kanji spelling; the ん is explicitly written as kana in this form.
Variant kanji form using 况 instead of 況; very rare.
A fossilized form of classical 言はむや, comprising 言ふ, the conjectural auxiliary む, and the rhetorical particle や: literally “would one even say?” It developed the emphatic sense “how much more” or “let alone.”