mother lode

American  

[muhth-er-lohd] / ˈmʌð ərˌloʊd /

Or motherlode

noun

1. Mining. a rich or important lode.

2. a major or profitable source or supply.

   New York City is a mother lode of actors.

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mother lode British  

noun

1. mining the principal lode in a system

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Etymology

Origin of mother lode

First recorded in 1855–60

Example Sentences

There are no mother lodes left to find.

From Barron's

But it could be a mother lode for small and large local news outlets, providing $500 million a year to preserve and grow local newsrooms.

From Seattle Times

But for a noir of isolation and concealment, about how the past can often feel inescapable, these shadowy dugouts — Travis’ motel, a church and one character’s lonely lair — are an atmospheric mother lode.

From Los Angeles Times

Two-thousand-five-hundred miles west of Dodger Stadium was a mother lode of Dodgers memorabilia.

From Los Angeles Times

The encyclopedia was crucial not only because it’s free and accessible, but also because it contains a mother lode of facts and so much of its material is consistently formatted.

From New York Times