民法典的规定：

第一百七十二条 【表见代理】行为人没有代理权、超越代理权或者代理权终止后，仍然实施代理行为，相对人有理由相信行为人有代理权的，代理行为有效。

百度百科给出的释义：

表见代理，是指被代理人的行为足以使第三人相信无权代理人具有代理权，并基于这种信赖而与无权代理人实施法律行为的代理。

表见代理的意义是承认外表授权；保护善意交易相对人的利益，使善意相对人不因相信表见代理人的行为发生了变化；保护动态交易安全。

简单来说，表见代理的行为人虽没有代理权，但第三人在客观上有理由相信其有代理权而与其实施法律行为，该法律行为的后果由本人承担的代理。

“表见代理”的英文表达为Apparent authority。

相关的英文释义如下：

In the United States, the United Kingdom, Australia, Canada and South Africa, apparent authority (also called "ostensible authority") relates to the doctrines of the law of agency. It is relevant particularly in corporate law and constitutional law. Apparent authority refers to a situation where a reasonable third party would understand that an agent had authority to act. This means a principal is bound by the agent's actions, even if the agent had no actual authority, whether express or implied. It raises an estoppel because the third party is given an assurance, which he relies on and would be inequitable for the principal to deny the authority given. Apparent authority can legally be found, even if actual authority has not been given.

There must be some act or some knowing omission on the part of the principal—if the agent alone acts to give the third party this false impression, then the principal is not bound. However, the principal will be bound if the agent so acts in the presence of the principal, and the principal stands silently and says nothing to dissuade the third party from believing that the agent has the authority to bind the principal. Apparent authority can also occur where a principal terminates the authority of an agent, but does not inform third parties of this termination. This is called lingering apparent authority. Business owners can avoid being liable by giving public notice of the termination of authority, and by contacting any individual third parties who would have had reason to know of such authority.

In relation to companies, the apparent authority of directors, officers and agents of the company is normally referred to as "ostensible authority." Apparent authority issues also arise in the Fourth Amendment context, concerning who has authority to consent to a search.

供参考。