Judgement on merits指的是实体判决，即法庭对案件经过庭审调查和辩论，以事实和证据为根据作出的确定当事人的实体权利的判决，除非上诉或因发现新证据要求旧案重审（reopen a case），当事人不能就同一案件再次提出诉讼。实体判决区别于判决有仅就案件的程序或法院管辖权问题作出的判决，以及未经审理的缺席判决（default judgement）等。

其英文释义如下：

A decision that was rendered after trail of the case (including argument and investigation) and made on the basis of the evidence introduced, as distinguished from a judgment rendered upon procedural errors or merely technical point, or by default and without trial. A party who has received a judgment on the merits cannot bring the same suit again.

在这里再补充一些关于实体判决和程序判决的知识。

有关实体法裁决与程序法裁决的驳回起诉：

Dismissal without prejudice即指的是程序法判决、非终局性驳回。It is a judgment that is not made on merits, but one based solely on some procedural errors. A party whose case has been dismissed without prejudice can bring the same suit again so long as the procedural errors are corrected in the later action. 此种驳回起诉不妨碍原告在以后以同一诉因再次起诉。

Dismissal without prejudice 实体法判决、不可再诉的驳回起诉。 A case dismissed with prejudice is over and done with, once and for all, and can't be brought back to court. 此种驳回起诉即为对案件实体问题作出的终局裁决，禁止原告在以后以同一诉因或请求再次起诉。