defect of speech vs speech disorder

defect of speech and speech disorder both are nouns.

Word	Noun	Adjective	Verb	Adverb
defect of speech	Yes	No	No	No
speech disorder	Yes	No	No	No

As nouns, defect of speech and speech disorder are synonyms defined as:

Other synonyms of defect of speech include speech defect.

defect of speech (noun)	speech disorder (noun)
a disorder of oral speech	a disorder of oral speech