rhumb line vs rhumb

rhumb line and rhumb both are nouns.

Word	Noun	Adjective	Verb	Adverb
rhumb line	Yes	No	No	No
rhumb	Yes	No	No	No

As nouns, rhumb line and rhumb are synonyms defined as:

rhumb line and rhumb: a line on a sphere that cuts all meridians at the same angle; the path taken by a ship or plane that maintains a constant compass direction

Other synonyms of rhumb line include loxodrome.

rhumb line (noun)	rhumb (noun)
a line on a sphere that cuts all meridians at the same angle; the path taken by a ship or plane that maintains a constant compass direction	a line on a sphere that cuts all meridians at the same angle; the path taken by a ship or plane that maintains a constant compass direction