Definition of Esquire
In English law, a title of dignity next above gentleman, and below knight. Also a title of office given to sheriffs, Serjeants, and barristers at law, justices of the peace, and others.
In United States, title commonly appended after name of attorney; e.g.John J. Jones, Esquire.
That's the definition of Esquire in Black's Law Dictionary 6th Edition. Courtesy of Cekhukum.com.