sham vs fictitious

sham is a noun but fictitious is not a noun.

Word	Noun	Adjective	Verb	Adverb
sham	Yes	Yes	Yes	No
fictitious	No	Yes	No	No

As adjectives, sham and fictitious are synonyms defined as:

Other synonyms of sham include assumed, false, fictive, pretended, put on.

sham (noun)	fictitious (noun)
something that is a counterfeit; not what it seems to be
a person who makes deceitful pretenses

sham (adjective)	fictitious (adjective)
adopted in order to deceive	adopted in order to deceive
	formed or conceived by the imagination

sham (verb)	fictitious (verb)
make believe with the intent to deceive
make a pretence of