the mother of something

the mother of all (something)

The largest, most extreme, or ultimate example of a particular kind of thing. The word that follows "of" is usually plural. Wow, that is the mother of all sandwiches. It's a foot high!
See also: all, mother, of

the ˈmother (and ˈfather) of (all) something

(informal) used to emphasize that something is very large, important, etc: There was the mother of all storms that night. It lasted for hours.Sorry we’re so late. We got stuck in the mother of all traffic jams on the way.
See also: mother, of, something