latissimus dorsi vs lat

latissimus dorsi and lat both are nouns.

Word	Noun	Adjective	Verb	Adverb
latissimus dorsi	Yes	No	No	No
lat	Yes	No	No	No

As nouns, latissimus dorsi and lat are synonyms defined as:

latissimus dorsi and lat: a broad flat muscle on either side of the back

latissimus dorsi (noun)	lat (noun)
a broad flat muscle on either side of the back	a broad flat muscle on either side of the back