Literal meaning

one (一) — cry (鸣) — astonish (惊) — people (人)

Origin

Records of the Grand Historian (《史记·滑稽列传》). A minister approached King Wei of Qi, who had ignored state affairs for three years, with a riddle: "There's a bird that has stayed in the king's palace for three years; it doesn't fly, it doesn't cry — what kind of bird is it?" The king answered: 此鸟不飞则已，一飞冲天；不鸣则已，一鸣惊人 — "This bird, if it doesn't fly, fine; but when it flies, it soars to the heavens. If it doesn't cry, fine; but when it cries, it astonishes everyone." He then turned around and ruled effectively. The phrase has carried the same meaning ever since: a long quiet period followed by a striking achievement.

Examples

Usage & nuances

Praise tone. Specifically captures the breakthrough-after-quiet shape — wouldn't fit someone who was always visible. Common in coverage of sports debuts, breakout movies, first-time award winners.