Language is a tool used for communication in every society, though manipulated by each society to suit its needs. In this regard, professions have their various registers. The diction used in a particular field makes it easy for the people in that field to communicate and understand one another. This means that communication becomes ineffective where registers are invariably used outside that field. The legal language for instance has its own structure and style, which are determined by the peculiar needs of the practitioners in the profession. This paper, by adopting the descriptive research method, has the major objective of exploring the semantics of the Nigerian legal language, which, as observed, has a complicated language system that acts as a wall dividing the legal practitioners and the public; in other words, the language is difficult for the comprehension of the layman. The second objective is to find out the role of linguistic theories in legal discourse and how they are used to achieve mutual intelligibility between the legal practitioners and the general public that they work for. The conclusion drawn from the analysis is that the Nigerian legal language is actually complicated and the judiciary is advised to use simple English and stop the use of archaic and out-dated Latin, French and English words. They should also reduce the use of double and triple prepositions in their statements to enhance mutual intelligibility.