mizen vs mizenmast

mizen and mizenmast both are nouns.

Word	Noun	Adjective	Verb	Adverb
mizen	Yes	No	No	No
mizenmast	Yes	No	No	No

As nouns, mizen and mizenmast are synonyms defined as:

mizen and mizenmast: third mast from the bow in a vessel having three or more masts; the after and shorter mast of a yawl, ketch, or dandy

Other synonyms of mizen include mizzen, mizzenmast.

mizen (noun)	mizenmast (noun)
third mast from the bow in a vessel having three or more masts; the after and shorter mast of a yawl, ketch, or dandy	third mast from the bow in a vessel having three or more masts; the after and shorter mast of a yawl, ketch, or dandy
fore-and-aft sail set on the mizzenmast