busy vs diligent

busy and diligent both are adjectives.

Word	Noun	Adjective	Verb	Adverb
busy	No	Yes	Yes	No
diligent	No	Yes	No	No

busy (adjective)	diligent (adjective)
actively or fully engaged or occupied	characterized by care and perseverance in carrying out tasks
overcrowded or cluttered with detail	quietly and steadily persevering especially in detail or exactness
intrusive in a meddling or offensive manner
(of facilities such as telephones or lavatories) unavailable for use by anyone else or indicating unavailability; (`engaged' is a British term for a busy telephone line)
crowded with or characterized by much activity

busy (verb)	diligent (verb)
keep busy with