fractional rig vs rigging

fractional rig and rigging both are nouns.

Word	Noun	Adjective	Verb	Adverb
fractional rig	Yes	No	No	No
rigging	Yes	No	No	No

As nouns, rigging is a hypernym of fractional rig; that is, rigging is a word with a broader meaning than fractional rig:

fractional rig: a rig on a sailing vessel that consists of a foresail, such as a jib or genoa sail, that does not reach all the way to the top of the mast.
rigging: formation of masts, spars, sails, etc., on a vessel

Other hypernyms of fractional rig include rig.

fractional rig (noun)	rigging (noun)
a rig on a sailing vessel that consists of a foresail, such as a jib or genoa sail, that does not reach all the way to the top of the mast.	gear consisting of ropes etc. supporting a ship's masts and sails
	formation of masts, spars, sails, etc., on a vessel