mother of all

Meanings

1. Used before a plural noun to form a compound noun having the sense of: the greatest or largest of (its kind); the most epic example of (its kind).

Etymology

Calque of Arabic أُمّ (ʔumm, “mother (of)”). Popularized and given its current sense by Saddam Hussein's claim that the impending Gulf War would be the أُمّ المَعَارِك (ʔumm al-maʕārik, “mother of (all) battles”), though mother had long been used in somewhat similar senses in English, and other familial terms are used with the same meaning, like granddaddy (of all traffic jams) and father (of all battles).