Imaginary
WordNet
adjective
(1) Not based on fact; dubious
"The falsehood about some fanciful secret treaties"- F.D.Roosevelt
"A small child's imaginary friends"
"Her imagined fame"
"To create a notional world for oneself"
noun
(2) (mathematics) a number of the form a+bi where a and b are real numbers and i is the square root of -1
WiktionaryText
Adjective
imaginary
- existing only in the imagination
- of a number, having no real part; that part of a complex number which is a multiple of the square root of -1.