defect of speech vs speech defect

defect of speech and speech defect both are nouns.

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

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

Other synonyms of defect of speech include speech disorder.

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