gnawing their fingernails in the air and on the ground中gnawing的内涵

问题描述:

gnawing their fingernails in the air and on the ground中gnawing的内涵
原文在上面的连接,没有搞清楚gnawing their fingernails中gnawing具体的内涵,

gnawing their fingernails : (啃他们的指甲) , 当人紧张时, 都啃指甲, 具体的内涵是 "捏一把冷汗"
因机场长度不够, 又近海洋, 飞机起降危险, 故机上旅客及机场候机客, 都捏一把冷汗.