Quid has various meanings: A pound sterling (£), in British slang, possibly derived from the Royal mint at Quidhampton, Wiltshire, England, but more likely from the Latin phrase 'Quid Pro Quo' (This for that)meaning an exchange of goods. A euro (?), in Irish slang An Irish punt or Australian pound (no longer issued) Quid , a French encyclopedia Quantitative Ingredient Declaration (QUID) On Food Labellinghttp://www.cspinet.org/reports/codex/qui