proficiency vs proficient

proficiency is a noun but proficient is not a noun.

Word	Noun	Adjective	Verb	Adverb
proficiency	Yes	No	No	No
proficient	No	Yes	No	No

proficiency (noun)	proficient (noun)
the quality of having great facility and competence
skillfulness in the command of fundamentals deriving from practice and familiarity

proficiency (adjective)	proficient (adjective)
	of or relating to technique or proficiency in a practical skill
	having or showing knowledge and skill and aptitude