Green’s Dictionary of Slang

used of a serious drinker.

[1914		‘Hugh McHugh’ You Should Worry cap. 1: His capacity for storing away free liquids was awe-inspiring and a sin. I think Ikey must have been hollow from the neck to the ankles].
1915		Sport (Adelaide) 12 Feb. 5/5: Sylvester M., the hollow-legged beer king.
1935		in R.E. Weinberg et al. Tough Guys (1993) 194: I think you’re a hollow-legged souse.
2004		review of Wellington Arkell, Best Bitters at www3.sympatico.ca 🌐 Let the pearls of wisdom from the hollow legged swillers begin.