You might be referring to a "Legal Assistant," or "Legal Aide." Someone who is skilled, or trained in the law but who has not studied law or passed the Bar Exam.
A person who has studied physics is called a physicist.
There is no preist in Sikhism but the person that leads the ceremonies and service is called a Granthi. Sometimes called a Giani (the learned) but the difference is that a Giani is one very well studied in the Sikh scriptures, a Giani will be specially trained in Northeren India.
Sometimes a duo.
A lazy person is sometimes colloquially known as a couch potato.
Abraham Lincoln
Many, many people have studied biochemistry in Mississippi.
It is not correct to say "they has studied". The correct way is to say "they have studied." There are many different places that a person can check grammar questions such as English grammar websites.
Geologists and vulcanologists.
A person who studies the Earth is called a geologist. A geologist mainly studies the origin of the Earth, its structure and composition.
sometimes called a "bird dog" fee.
A person who sees and talks to ghosts is sometimes called a spirit medium.
A "Writ of Extradtion" sometimes called a "Governor's Warrant."