X vs decade

X and decade both are nouns.

Word	Noun	Adjective	Verb	Adverb
X	Yes	No	No	No
decade	Yes	No	No	No

As nouns, X and decade are synonyms defined as:

X and decade: the cardinal number that is the sum of nine and one; the base of the decimal system

Other synonyms of X include 10, ten, tenner.

X (noun)	decade (noun)
street names for methylenedioxymethamphetamine	the cardinal number that is the sum of nine and one; the base of the decimal system
the 24th letter of the Roman alphabet	a period of 10 years
the cardinal number that is the sum of nine and one; the base of the decimal system