mother lode vs lode

mother lode and lode both are nouns.

Word	Noun	Adjective	Verb	Adverb
mother lode	Yes	No	No	No
lode	Yes	No	No	No

As nouns, lode is a hypernym of mother lode; that is, lode is a word with a broader meaning than mother lode:

mother lode: the main vein of ore in a deposit
lode: a deposit of valuable ore occurring within definite boundaries separating it from surrounding rocks

Other hypernyms of mother lode include load.

mother lode (noun)	lode (noun)
the main vein of ore in a deposit	a deposit of valuable ore occurring within definite boundaries separating it from surrounding rocks