phobia vs anxiety disorder

phobia and anxiety disorder both are nouns.

Word	Noun	Adjective	Verb	Adverb
phobia	Yes	No	No	No
anxiety disorder	Yes	No	No	No

As nouns, anxiety disorder is a hypernym of phobia; that is, anxiety disorder is a word with a broader meaning than phobia:

phobia: an anxiety disorder characterized by extreme and irrational fear of simple things or social situations
anxiety disorder: a cover term for a variety of mental disorders in which severe anxiety is a salient symptom

phobia (noun)	anxiety disorder (noun)
an anxiety disorder characterized by extreme and irrational fear of simple things or social situations	a cover term for a variety of mental disorders in which severe anxiety is a salient symptom