covertly
01
秘密地, 暗中
with the intention of keeping actions, plans, or operations secret
例子
The intelligence agency operated covertly to gather information on the enemy.
情报机构秘密行动以收集关于敌人的信息。
The undercover agent observed the criminal activities covertly.
卧底特工秘密观察了犯罪活动。
