Legal derives from the Latin legalis, meaning “of the law" (lex)
Generally used as a pejorative term for written forms of legal English, legalese is characterized by verbosity, Latin expressions, nominalizations, embedded clauses, passive verbs, and lengthy sentences.
“Legalese is one of the few social evils that can be eradicated by careful thought and disciplined use of a pen. It is doubly demeaning: first it demeans its writers, who seem to be either deliberately exploiting its power to dominate or are at best careless of its effects; and second it demeans its readers by making them feel powerless and stupid."
(Martin Cutts, Oxford Guide to Plain English, 3rd ed. Oxford University Press, 2009)

-
“An American Bar Foundation study found in 1992 that employers believe that the biggest problem with recent law graduates is that they don’t know how to write. And the graduates themselves say that writing is the part of their jobs that their legal education has least equipped them to do competently (let alone artfully, easily, beautifully)…"
-
“Those who see legal writing as being simply a matter of cleaning up grammar and punctuation, as well as learning citation form, grossly misunderstand what the field should be. Good writing results from good, disciplined thinking. To work on your writing is to improve your analytical skills."
(Bryan A. Garner, “The Mad, Mad World of Legal Writing." Garner on Language and Writing. American Bar Association, 2009)