spar vs fit out

spar is a noun but fit out is not a noun.

Word	Noun	Adjective	Verb	Adverb
spar	Yes	No	Yes	No
fit out	No	No	Yes	No

As verbs, fit out is a hypernym of spar; that is, fit out is a word with a broader meaning than spar:

Other hypernyms of spar include equip, fit, outfit.

spar (noun)	fit out (noun)
making the motions of attack and defense with the fists and arms; a part of training for a boxer
a stout rounded pole of wood or metal used to support rigging
any of various nonmetallic minerals (calcite or feldspar) that are light in color and transparent or translucent and cleavable

spar (verb)	fit out (verb)
fight verbally	provide with clothes or put clothes on
box lightly	provide with (something) usually for a specific purpose
fight with spurs
furnish with spars