abdominal vs skeletal muscle

abdominal and skeletal muscle both are nouns.

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

As nouns, skeletal muscle is a hypernym of abdominal; that is, skeletal muscle is a word with a broader meaning than abdominal:

abdominal: the muscles of the abdomen
skeletal muscle: a muscle that is connected at either or both ends to a bone and so move parts of the skeleton; a muscle that is characterized by transverse stripes

Other hypernyms of abdominal include striated muscle.

abdominal (noun)	skeletal muscle (noun)
the muscles of the abdomen	a muscle that is connected at either or both ends to a bone and so move parts of the skeleton; a muscle that is characterized by transverse stripes

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