woodpecker (n.)

Old English wudu, earlier widu "tree, trees collectively, forest, grove; the substance of which trees are made," from Proto-Germanic *widu- (source also of Old Norse viðr, Danish and Swedish ved "tree, wood," Old High German witu "wood"), from PIE *widhu- "tree, wood" (source also of Welsh gwydd "trees," Gaelic fiodh- "wood, timber," Old Irish fid "tree, wood"). Out of the woods "safe" is from 1792.

1690s, "one who or that which pecks," agent noun from peck (v.); slang sense of "penis" is from 1902, according to OED "chiefly U.S." OED adds that the British colloquial sense of "courage, resolution" (in keep your pecker up, 1853) is "commonly avoided by British travellers in the U.S."

1859, U.S. Southern black dialectal inversion of woodpecker; in folklore, taken as the type of white people, especially poor whites (1929), and symbolically contrasted with blackbird.