LEXIST (Technically LEXist or Lexist) is someone well versed or otherwise a legal expert or a centre of knowledge of law and legal matters. (Not to be confused with the US term Jurist).
From the word stem LEX , being the Latin word for "law" or "statute"; See List of Roman laws. Lex (Canon law), in Roman Catholic canon law
, typical uses being EUR-Lex which is the repository for all European-Union (European Community) Law and from where the legal phrase Lex Loci arises (i.e. the law of the place).
lex (lɛks) n, pl leges (ˈli dʒi z)Latin
being a system or body of laws, a particular specified law or a repository of legal knowledge.