adj.无防备的，无警戒的，无保护的，不小心的，不谨慎的，不留神的

She let down her guard and confided in him about her fears.
她放松了警惕，向他倾诉了自己的恐惧。
The unguarded moment revealed his true feelings.
这个不经意的瞬间暴露了他的真实情感。
The unguarded border allowed for illegal crossings.
未设防的边境使得非法穿越成为可能。
The athlete's unguarded ankle was vulnerable to injury.
运动员未受保护的脚踝容易受伤。
In his unguarded speech, he admitted to past mistakes.
在他毫无防备的发言中，他承认了过去的错误。
The child's unguarded enthusiasm was infectious.
孩子毫无保留的热情很有感染力。
The politician's unguarded comments sparked controversy.
这位政治家未经掩饰的言论引发了争议。
The unguarded email contained sensitive company information.
这封未经加密的电子邮件包含了敏感的公司信息。
The village remained unguarded during the night, leaving it exposed.
村庄在夜间没有设防，使其暴露在外。
His unguarded smile showed his genuine happiness.
他无拘无束的笑容显示出他真正的快乐。