innocent vs innocuous

innocent is a noun but innocuous is not a noun.

Word	Noun	Adjective	Verb	Adverb
innocent	Yes	Yes	No	No
innocuous	No	Yes	No	No

As adjectives, innocent and innocuous are synonyms defined as:

innocent (noun)	innocuous (noun)
a person who lacks knowledge of evil

innocent (adjective)	innocuous (adjective)
free from evil or guilt	not injurious to physical or mental health
lacking intent or capacity to injure	lacking intent or capacity to injure
lacking in sophistication or worldliness	not causing disapproval
completely wanting or lacking
(used of things) lacking sense or awareness
not knowledgeable about something specified
free from sin