fullness vs repletion

fullness and repletion both are nouns.

Word	Noun	Adjective	Verb	Adverb
fullness	Yes	No	No	No
repletion	Yes	No	No	No

As nouns, repletion is a hyponym of fullness; that is, repletion is a word with a more specific, narrower meaning than fullness:

fullness: the condition of being filled to capacity
repletion: the state of being satisfactorily full and unable to take on more

Other hyponyms of fullness include satiation, satiety, excess, overabundance, surfeit, solidity, infestation.

fullness (noun)	repletion (noun)
greatness of volume	eating until excessively full
the property of a sensation that is rich and pleasing	the state of being satisfactorily full and unable to take on more
the condition of being filled to capacity
completeness over a broad scope