decay vs dilapidate

decay is a noun but dilapidate is not a noun.

Word	Noun	Adjective	Verb	Adverb
decay	Yes	No	Yes	No
dilapidate	No	No	Yes	No

As verbs, decay and dilapidate are synonyms defined as:

Other synonyms of decay include crumble.

decay (noun)	dilapidate (noun)
the organic phenomenon of rotting
a gradual decrease; as of stored charge or current
the process of gradually becoming inferior
the spontaneous disintegration of a radioactive substance along with the emission of ionizing radiation
an inferior state resulting from the process of decaying

decay (verb)	dilapidate (verb)
fall into decay or ruin	fall into decay or ruin
lose a stored charge, magnetic flux, or current	bring into a condition of decay or partial ruin by neglect or misuse
undergo decay or decomposition