delta vs alluvial deposit

delta and alluvial deposit both are nouns.

Word	Noun	Adjective	Verb	Adverb
delta	Yes	No	No	No
alluvial deposit	Yes	No	No	No

As nouns, alluvial deposit is a hypernym of delta; that is, alluvial deposit is a word with a broader meaning than delta:

delta: a low triangular area of alluvial deposits where a river divides before entering a larger body of water
alluvial deposit: clay or silt or gravel carried by rushing streams and deposited where the stream slows down

Other hypernyms of delta include alluvial sediment, alluvion, alluvium, formation, geological formation.

delta (noun)	alluvial deposit (noun)
the 4th letter of the Greek alphabet	clay or silt or gravel carried by rushing streams and deposited where the stream slows down
a low triangular area of alluvial deposits where a river divides before entering a larger body of water
an object shaped like an equilateral triangle