diligence vs assiduity

diligence and assiduity both are nouns.

Word	Noun	Adjective	Verb	Adverb
diligence	Yes	No	No	No
assiduity	Yes	No	No	No

As nouns, assiduity is a hyponym of diligence; that is, assiduity is a word with a more specific, narrower meaning than diligence:

Other hyponyms of diligence include assiduousness, concentration, sedulity, sedulousness, studiousness.

diligence (noun)	assiduity (noun)
a diligent effort	great and constant diligence and attention
persevering determination to perform a task
conscientiousness in paying proper attention to a task; giving the degree of care required in a given situation