sonk(e)y, n. — Green’s Dictionary of Slang

sonk(e)y n.

also sonkie

[dial. sonkie, a man like a sackful of straw]

1. a thug.

1890–1904

2. a foolish, clumsy person.

1873		Sl. Dict. 302: Sonkey a clumsy, awkward fellow.
1886		Reynold’s Newspaper (London) 12 Dec. 2/2: You’ll be sky-wannocking upon nothing shortly, my fine soor sonkey.
1890–1904		Farmer & Henley Sl. and Its Analogues.

3. (Aus.) an upper-class weakling.

1917

C.J. Dennis ‘Washing Day’ in Chisholm (1951) 68: Aw, I ain’t no silk-sock sonkie ’oo abhors the rood and rough.