c. 1200, likur "any matter in a liquid state, a liquid or fluid substance," from Old French licor "fluid, liquid; sap; oil" (12c., Modern French liqueur), from Latin liquorem (nominative liquor) "a liquid, liquor; wine; the sea," originally "liquidity, fluidity," from liquere "be fluid, liquid" (see liquid (adj.)).
Narrowed sense of "fermented or distilled drink" (especially wine) first recorded c. 1300; the broader sense seems to have been obsolete from c. 1700. As long as liquor is in him was a Middle English expression, "as long as he is alive," that is, "as long as he has a drop of blood left." The form in Modern English has been assimilated to Latin, but the old pronunciation persists.