flavorlessness vs flavourlessness

flavorlessness and flavourlessness both are nouns.

Word	Noun	Adjective	Verb	Adverb
flavorlessness	Yes	No	No	No
flavourlessness	Yes	No	No	No

As nouns, flavorlessness and flavourlessness are synonyms defined as:

Other synonyms of flavorlessness include savorlessness, savourlessness, tastelessness.

flavorlessness (noun)	flavourlessness (noun)
the property of having no flavor	the property of having no flavor