patient vs diligent

patient is a noun but diligent is not a noun.

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

patient (noun)	diligent (noun)
the semantic role of an entity that is not the agent but is directly involved in or affected by the happening denoted by the verb in the clause
a person who requires medical care

patient (adjective)	diligent (adjective)
enduring trying circumstances with even temper or characterized by such endurance	characterized by care and perseverance in carrying out tasks
	quietly and steadily persevering especially in detail or exactness