Definition of "esquire"

I am Robert Shallow, sir; a poor esquire of the county, and one of the king's justices of the peace.

c. 1596–1599 (date written), William Shakespeare, “The Second Part of Henry the Fourth, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene ii]

Esquires and gentlemen are confounded together by Sir Edward Coke, who observes that every esquire is a gentleman, and a gentleman is defined to be one qui arma gerit, who bears coat-armour, the grant of which was thought to add gentility to a man's family. It is indeed a matter somewhat unsettled what constitutes the distinction, or who is a real esquire; for no estate, however large, per se confers this rank upon its owner.

1875 Herbert Broom and Edward Hadley, notes by William Wait, Commentaries on the laws of England, I-317

The office of the esquire consisted of several departments; the esquire for the body, the esquire of the chamber, the esquire of the stable, and the carving esquire; the latter stood in the hall at dinner, carved the different dishes, and distributed them to the guests.

1801, Joseph Strutt, The Sports and Pastimes of the People of England

Thre pallets between ij Esquires bast dexter and sinister of the second.

1597, Gerard Legh, Armorie, page 154, quoted in the NED

Mortimer, Barry of 6, or & az. an inescutcheon arg. on a chief of the first 2 pallets between as many base esquires of the second.

1883, Transactions of the Shropshire Archaeological and Natural History Society, page 142

Against the theory of two wives for Sir Thomas, is the fact that the Lumley Monument mentions only one, Elizabeth. In addition she appears to have been granted the Royal Arms: 1. France and England, 2. a plain cross of Ulster, 3. as 2, 4. barry of siz, a chief three pallets, between two esquires bastions, dexter and sinister, an inescutcheon Argent, Mortimer, over all a bar sinister, which are also displayed on the monument.

2011 October 24, Peter Beauclerk-Dewar, Roger Powell, Royal Bastards: Illegitimate Children of the British Royal Family, The History Press