An advocate, counsel, official agent employed in preparing, managing, and trying cases in the courts. An officer in a court of justice, who is employed by a party in a cause to manage the same as he do.

In English law. An attorney at law was a public officer belonging to the superior courts of common law at Westminster, who conducted legal proceedings on behalf of others, called his clients, by whom he was retained; he answered to the solicitor in the courts of chancery, and the proctor of the admiralty, ecclesiastical, probate, and divorce courts. An attorney was almost invariably also a solicitor. It is now provided by the judicature act, 1873.

A person admitted to practice law in at least one jurisdiction and authorized to perform criminal and civil legal functions on behalf of clients. These functions include providing legal counsel, drafting legal documents, and representing clients before courts, administrative agencies, and other tribunals.

Unless a contrary meaning is plainly indicated this term is synonymous with "attorney at law,""lawyer," or "counselor at law."

In order to become an attorney, a person must obtain a Juris Doctor degree from an accredited law school, although this requirement may vary in some states. Attendance at law school usually entails three years of full-time study, or four years of study in evening classes, where available. A bachelor's degree is generally a prerequisite to admission to law school.

With few exceptions, a person must pass the bar examination of that state in order to be admitted to practice law there. After passing a bar examination and practicing law for a specified period, a person may be admitted to the bars of other states, pursuant to their own court rules.

Although the terms often operate as synonyms, an attorney is a lawyer but a lawyer is not necessarily an attorney. To the general public, these terms may be used interchangeably but to the American Bar Association, the slight distinction is significant.

In other common law jurisdictions around the world such as England and Wales, more specific distinctions are drawn. There, they differentiate between those who practice law in court and those who do not by the use of terms such as solicitors, barristers, and advocates. In other countries, public notaries are also distinguished from attorneys.

A solicitor is a lawyer who deals with any legal matter. Typically, they don’t appear in court but prepare legal documents and work directly with clients providing legal advice. Historically, the term solicitor was used in the United States. It was referred to lawyers who handled cases in a court of equity. Whereas attorneys, at that time, only dealt with cases in a court of law.

On the other hand, barristers are called upon by solicitors if their case requires a court appearance. A barrister doesn’t work directly with clients but receives referrals from solicitors who are often retained by their clients. The solicitor will assist the barrister with all preparations for the case outside of court. Although this is not always the case, an advocate is another term for barrister in many English-law based jurisdictions.

An additional term used is esquire. It is employed at the end of an attorney’s name, abbreviated as Esq. Its purpose is to give an honorary title. Similar to the use of the abbreviations Dr. or Ph.D., it also signifies a professional title. Its origins are in England where the title was once reserved for males, as a term of respect for those of high social rank.

Esquire is a title one may tack on without the approval of the American Bar Association or any other legal entity. Therefore, it can be somewhat controversial. Some have added it to their names without having obtained the actual qualifications. This gives the false perception of their ability to legally practice law. Therefore, it serves to be cautious and not presumptuous when encountering this term.

Attorney at law or attorney-at-law, usually abbreviated in everyday speech to attorney, is the preferred term for a practicing lawyer in certain jurisdictions, including South Africa (for certain lawyers), Sri Lanka, and the United States. In Canada, it is used only in Quebec. The term has its roots in the verb to attorn, meaning to transfer one's rights and obligations to another.