This is the 3562nd most frequent Chinese word.
消息人士
"消息人士" means "source" or "informed person."
消息人士 is used here to refer to a source providing specific information about events.
根据消息人士透露,新的贸易协议即将签署。
According to an informant, the new trade agreement is about to be signed.
In this sentence, 消息人士 means a person actively supplying information to others.
他经常作为消息人士向新闻媒体提供第一手信息。
He often acts as an informant, providing first-hand information to the news media.
Here, 消息人士 represents a person who shares information while keeping their identity concealed.