peg, v.⁶ — Green’s Dictionary of Slang

peg v.⁶

[? one has put the peg into one’s stomach, i.e. blocked it off; ? var. on SE beg]

(Aus.) to starve; thus pegging for, desperate for.

1919		L. Esson Drovers (1977) 6: But the trouble is they’re still pegging for a drink.
1928		V. Palmer Passage 283: She’s come a long way and must be pegging for a drink and a feed.