mother of all

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).

• ", etc."
• "Near-synonym: Big One"
• "Driving to a dinner engagement, a Parisian woman gets stuck in the mother of all traffic jams, offers a ride to a handsome pedestrian, and enters a fleeting affair that catches both of them by surprise."
• "Five mail-order ice creams. Four pregnant women. Welcome to the mother of all taste tests."
• "“[Donald Trump's tariff proposal] is a prescription for the mother of all stagflations,” Larry Summers, Treasury secretary during the Clinton administration, told Bloomberg TV back in June."

• father
• granddaddy
• grandmammy
• Big One

• mother