Green’s Dictionary of Slang

bord n.

a shilling (5p).

c.1566		Harman Caveat for Common Cursetours in Viles & Furnivall (1907) 83: a bord a shylling.
1592		Groundworke of Conny-catching A2: A borde, a shilling; halfe a borde, six pence.
1608		Dekker The Belman of London (3rd) J4: Bowse there a board & thou shalt haue benship.
1611		Middleton & Dekker Roaring Girle V i: These gentlemen bestows upon you two boards and a half, that’s two shillings sixpence.
1612		Dekker ‘Of Clapperdogeons’ O per se O N2: Their Doxies will trauell [...] from Fayre to Fayre, from Market to Market, being able by their Maunding to get fiue Bordes (that is, fiue shillings) in a weeke.
1639		J. Taylor Crabtree Lectures 189: Cove. Mort, what lower hast thou in thy Bung? Cove. I have a boord, two stagges, a Make, and one jon, and a rum stocke too.
1665		Head Eng. Rogue I 47: Borde, A Shilling.
1674		Head Canting Academy (2nd edn).
1688		R. Holme Academy of Armory Ch. iii item 68c: Canting Terms used by Beggars, Vagabonds, Cheaters, Cripples and Bedlams. [...] Borde, a shilling.
c.1698		B.E. Dict. Canting Crew n.p.: Borde c, a Shilling.
1707		J. Shirley Triumph of Wit (5th edn).
1714		A. Smith Lives of Most Noted Highway-men, etc. I 209: He taught his Pupil a deal of canting Words, telling him [...] Borde a Shilling.
1724		‘John Sheppard’s Last Epistle’ in Dly Jrnl (London) 16 Nov. 1: Pray send me some Peck and some Bub, / A Slat or a Board to the Needy.
1725		Life and Glorious Actions of [...] Jonathan Wilde 25: These bottles of Wine [...] are sold for two Bords per Bottle, viz. Two Shillings per Bottle.
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. n.p.: borde c. a Shilling, half a Borde, c. Sixpence.
1741		Canting Academy, or the Pedlar’s-French Dict. 113: Five Shillings Five Boards.
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Borde, a shilling. A half borde; a sixpence.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.
1881		Morn. Bulletin (Rockhampton, Qld) 18 July 2/6: For a shilling there are many names but nearly all slang. [...] ‘Breaky-leg,’ ‘brongs,’ ‘bobs,’ ‘bordes,’ ‘drawers,’ ‘gens’, ‘hogs,’ levys,’ ‘pegs,’ ‘stags,’ ‘Shigs,’ ‘twelvers’ and ‘teviss’s’ .

In phrases

half-(a-)bord(e) (n.)

(UK Und.) a sixpence (5p).

c.1566		Harman Caveat for Common Cursetours in Viles & Furnivall (1907) 83: halfe a borde, sixe pence.
1592		Groundworke of Conny-catching [as cit. c.1566].
1608		Dekker Lanthorne and Candle-Light Ch. 1: The Canters Dictionarie: Half a Borde, six pence.
1610		Rowlands Martin Mark-all 37: Halfe a Boord, sixepence.
1665		Head Eng. Rogue I 50: Half bord, Six pence.
1674		Head Canting Academy (2nd edn) 175: Half bord Sixpence.
1688		R. Holme Academy of Armory Ch. iii item 68c: Canting Terms used by Beggars, Vagabonds, Cheaters, Cripples and Bedlams. [...] Half a Borde, six pence.
c.1698		B.E. Dict. Canting Crew.
1719		A. Smith Lives of Most Notorious Highway-men, etc. (1926) 203: Borde, a shilling. Half a borde, sixpence.
c.1750–1882		B.M. Carew Life and Adventures.
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue n.p.: Half bord, sixpence.
1809		G. Andrewes Dict. Sl. and Cant n.p.: half-bound sixpence.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.