Mother lode singular noun countable noun
A main vein of a mineral in a given area
They failed to find the mother lode of gold.
A large quantity of something
Oh! You are so lucky today with a basket full of fish. You hit the mother lode!.
Her personal life experiences have given her a mother lode of material for her current job.
Adequate measures or actions
"Mother lode" was originally an American mining word that referred to the primary vein of ore in a region from 1855 to 1860, but it is now commonly used figuratively to refer to any plentiful supply of something.
very excited and interested
Children are as keen as mustard to discover new things around them.