To have on good authority means to possess information that is reliable, trustworthy, and obtained from a credible source. When someone says they have something on good authority, it implies that they have received the information from a credible or knowledgeable individual who has firsthand knowledge or expertise in the subject matter.
This expression often suggests that the information being relayed is likely accurate and can be relied upon. It implies that the source of the information is not only trustworthy but also has a high level of credibility due to their expertise, position, or access to relevant facts. It can also indicate that the person sharing the information has verified its accuracy through cross-checking or confirming it with other trustworthy sources.
Having something on good authority can be particularly important when dealing with topics that require factual accuracy, such as news reports, scientific research, legal matters, or confidential information. It conveys that the information being relayed is not mere gossip or speculation but has a solid foundation in truth and has been authenticated through reliable channels.
Using reliable sources and obtaining information on good authority is essential in ensuring the accuracy and credibility of information for making informed decisions, reporting news, conducting research, or any other process that relies on factual information.