1. (a.) Existing only in imagination or fancy; not real\; fancied; visionary; ideal.

2. (n.) An imaginary expression or quantity.

Barmecidal Barmecide abstract air-built airy algorismic algorithmic aliquot apparent apparitional autistic cardinal chimeric chimerical cloud-built deceptive decimal delusional delusionary delusive delusory dereistic differential digital dreamlike dreamy erroneous ethereal even exponential fallacious FALSE fancied fanciful fantastic fatuitous fatuous fictional fictitious fictive figmental figural figurate figurative finite fractional gaseous gossamery hallucinatory hypothetical ideal illusional illusionary illusive illusory imaginational imaginative imagined immaterial impair impossible infinite integral irrational legendary logarithmic logometric made-up merely nominal misleading mythic mythical mythological negative nonexistent not real notional numeral numerary numerative numeric odd ordinal ostensible pair phantasmagoric phantasmal phantasmic phantom phantomlike positive possible prime quixotic radical rarefied rational real reciprocal seeming self-deceptive self-deluding shadowy specious spectral spirituous submultiple subtile subtle supposititious surd tenuous transcendental unactual unfounded unreal unrealistic unsubstantial untrue vaporous visional visionary windy