noun
volcanic crater rim; the rim of a volcano
Specifically refers to the sharp, sword-like ridge around a volcanic crater, most famously associated with Mt. Fuji. Often used in the phrase 剣が峰に立つ (to stand on the rim) metaphorically.
富士山の剣が峰は、登山者にとって最後の難所だ。
The crater rim of Mt. Fuji is the final challenge for climbers.
noun
sumo ring; wrestling ring
In sumo, the raised ring where matches take place. The term evokes the idea of a critical boundary, similar to the crater rim.
力士が剣が峰に上がると、観客の拍手が湧き起こった。
When the wrestler stepped onto the ring, applause erupted from the audience.
noun
critical situation; sink-or-swim moment; do-or-die position
Metaphorical use derived from the crater rim sense. Describes a high-stakes situation with no room for error, where one wrong move leads to disaster. Common in business, sports, and personal crises.
会社は資金繰りが厳しく、まさに剣が峰に立たされている。
The company is in a dire cash-flow situation, truly standing on the brink.
試合は最終セット、剣が峰の場面でエースが決まった。
In the final set, at the critical moment, an ace was scored.
Literally 'sword peak' (剣 = sword, 峰 = peak). Originally referred to the sharp, sword-like ridge of a volcanic crater, especially on Mt. Fuji. The metaphorical sense of a critical situation comes from the image of standing on a narrow, dangerous ridge.