noun
Military term for a small unit sent ahead of the main force to scout or secure a position.
尖兵が敵の陣地を偵察した。
The advance guard scouted the enemy position.
Figurative extension: a person or group leading the way in a new field, movement, or trend.
彼は業界の尖兵として新しい技術を広めた。
He spread new technology as a pioneer in the industry.
先駆者 is a more common word for 'pioneer' or 'forerunner' in non-military contexts. 尖兵 retains a stronger military flavor even when used figuratively.
Compound of 尖 (point, tip) and 兵 (soldier), literally 'point soldier'. The figurative sense developed from the military meaning.