[Pet-form of the name WILLIAM.] Applied locally to various animals; e.g., the guillemot, = WILLOCK; also attrib., as in willy-goat, a he-goat (= BILLY-GOAT); willy-wagtail, (a) the water wagtail; (b) in Australia, = WAGTAIL sb. 2 b. (See also WILL-O’-THE-WISP 1 e.)
1849. Zoologist, VII. 2393. The common guillemot is a ‘willy.’
1883. Sunday Mag., Aug., 528/1. Some birds flying … over the vessel … called willies.
1852. W. Wickenden, Hunchback’s Chest, 82. You might have broken the leg of the willy-goat.
1824. Mactaggart, Gallovid. Encycl., *Wullie-Wagtail.
1885. Mrs. C. Praed, Head Station (new ed.), 156. A brisk little willy-wagtail hopping about on the gravel.
