Where does “on the grog” come from?

on the grog (English) comes from English grog, from Latin crocum, from Ancient Greek κρόκος — saffron, "Crocus sativus"; saffron; yolk.

Ancestry of “on the grog”, step by step

StepLanguageWordMeaning
1EnglishgrogAn alcoholic beverage made with rum and water,...
2LatincrocumAlternative form of crocus; saffron
3Ancient Greekκρόκοςsaffron, "Crocus sativus"; saffron; yolk
Every word from Ancient Greek κρόκος →Every word from Latin crocum →Every word from English grog →