英和和英

語源

Probably a calque of Spanish veta madre (“mother lode”).

発音

名詞

mother lode (複数形 mother lodes)

1. (geology) A large or rich vein of gold or of another precious mineral from which other branches extend.
   • 1912, Jack London, “The Little Man”, in Smoke Bellew:

     Undeterred, reasoning from the coarseness of the gold that it had not traveled far, they had set out in search of the mother lode.

2. (idiomatic, by extension) Any source of valuable or useful material.
   • 2000 April 10, Dick Thompson, “The Feds Step Up the Pace”, in Time‎^[1]:

     It is also letting them probe the genomes of other organisms for DNA that could turn out to be a mother lode for medicine.

   • 2014 March 4, Landon Thomas Jr., “Emerging, but No Longer a Mother Lode of Profits”, in New York Times‎^[2]:

     Emerging, but No Longer a Mother Lode of Profits [title]

Further reading

• mother lode on Wikipedia.

語源

From mother +‎ lode.

名詞

motherlode (複数形 motherlodes)

1. (literally) The main, central lode of a natural resource, near which smaller deposits of the same ore etc. exist.

   Once the Western mining company has exploited a motherlode with state of the art equipment, it often abandons the minor lodes to primitive local enterprise

2. (figuratively) The main prize, best cut or pick etc. by far, dwarfing all others.

   Luckily the philistine castle-burglars missed the motherlode: his lordship's historical memorabilia collection

同意語

• (比喩的に): lion's share