1.having descriptive value as distinguished from syntactic category;
sex is a notional category; gender is a syntactic one
2.not based on fact; dubious;
the falsehood about some fanciful secret treaties- F.D.Roosevelt
3.not based on fact or investigation;
a notional figure of cost helps in determining production costs
4.indulging in or influenced by fancy;
a fanciful mind
5.being (or being of the nature of) a notion or concept;
a plan abstract and conceptional