noun
whistling arrow; signal arrow
A traditional Japanese arrow with a wooden or horn bulb (鏑) that whistles in flight. Historically used to signal the start of battle or in Shinto rituals. Also used figuratively as 'the beginning' or 'harbinger' (see 嚆矢).
See also: 嚆矢
合戦の合図に鏑矢が放たれた。
A whistling arrow was shot as the signal to begin the battle.
神社の儀式で鏑矢が使われることがある。
Whistling arrows are sometimes used in Shinto rituals.
嚆矢 is a literary synonym for 鏑矢, but more often used figuratively to mean 'the beginning' or 'pioneer' of something.
Compound of かぶら (turnip-shaped bulb) + 矢 (arrow). The whistling sound is produced by air passing through holes in the bulb.