abdominal vs abdominal muscle

abdominal and abdominal muscle both are nouns.

Word	Noun	Adjective	Verb	Adverb
abdominal	Yes	Yes	No	No
abdominal muscle	Yes	No	No	No

As nouns, abdominal and abdominal muscle are synonyms defined as:

Other synonyms of abdominal include ab.

abdominal (noun)	abdominal muscle (noun)
the muscles of the abdomen	the muscles of the abdomen

abdominal (adjective)	abdominal muscle (adjective)
of or relating to or near the abdomen