A person who secretly gathers information for a group or state.

• Someone who watches others covertly to gain advantage.

为团体或国家秘密收集情报的人。

• 为获取优势而暗中监视他人的人。

In American football, a defender assigned to shadow a mobile backfield player, often the quarterback.

• A player who monitors and contains a specific runner on potential scrambles.

在美式橄榄球中，负责盯防机动性强的后场球员（常为四分卫）的防守者。

• 在可能的突破跑动中专门监控并限制特定持球手的球员。

To act as a spy and gather information covertly.

• To secretly watch someone or something for intelligence.

充当间谍，秘密获取信息。

• 为获取情报而暗中监视某人或事物。

To notice or catch sight of, especially after searching.

• To spot something unexpectedly or from a distance.

注意到或看见，尤指经过寻找后。

• 意外或远处发现某物。