espial
/ɪˈspaɪəl/noun
mass noun
- archaic the action of watching or catching sight of something or someone or the fact of being seen〈古〉窥探, 侦察; 窥见, 发现; 被看见：
he withdrew from his point of espial.
他从他的观察点撤了回来。
词源
late Middle English （in the sense 'spying'）： from Old French espiaille， from espier 'espy'.