Green’s Dictionary of Slang

1. (UK Und.) in a crooked gambling game, the accomplice who urges on the victim, helping him by providing a succession of small stakes.

1608		Dekker Lanthorne and Candle-Light Ch. 3: He that stands by & Ventures, is the Woodpecker.
1685		New plot newly discovered 4: The Forlorne-Hope doth gallantly come on, the Eagle feathers his nest, the Wood-pecker picks up his crumbs, the Gull-groper grows fat [...] and the Gull himself [has] scarce enough to keep his back warm .
c.1698		B.E. Dict. Canting Crew n.p.: Woodpecker c. a Bystander that bets.
1725		New Canting Dict. [as cit. c.1698].
1737, 1759, 1760, 1776		Bailey Universal Etym. Eng. Dict. [as cit. c.1698].
1785, 1788, 1796		Grose Classical Dict. of the Vulgar Tongue.
1811		Lex. Balatronicum.
1823		Egan Grose’s Classical Dict. of the Vulgar Tongue.

2. (US Und.) a typist.

1950

Goldin et al. DAUL 238/2: Woodpecker. A typist.

3. (US/Aus.) a machine-gun [the tapping noise].

1957		J.M. Hosking ‘Duel at Dawn’ Aus. First and Last 107: There the ‘woodpecker’ rapped out a melody; our Bren’s reply was terse.
1968		J. Alard He who Shoots Last 225: ‘Dat ain’t no woodpecker.’ ‘Da lousy bludgers is usin’ a jazz gun on us. All we has got is a .45. It ain’t sportin’.’.

4. (W.I.) a district police officer [the red stripes on their uniform, reminiscent of the bird’s colouring].

1952

cited in Cassidy & LePage Dict. Jam. Eng. (1980).