[imag.i.nary] adj (14c) 1 a: existing only in imagination: lacking factual reality b: formed or characterized imaginatively or arbitrarily "his canvases, chiefly ~, somber landscapes --Current Biog."
2: containing or relating to the imaginary unit "~ roots" -- imag.i.nari.ly adv -- imag.i.nari.ness n syn imaginary, fanciful, visionary, fantastic, chimerical, quixotic mean unreal or unbelievable. imaginary applies to something which is fictitious and purely the product of one's imagination "an imaginary desert isle". fanciful suggests the free play of the imagination "a teller of fanciful stories". visionary stresses impracticality or incapability of realization "visionary schemes". fantastic implies incredibility or strangeness beyond belief "a fantastic world inhabited by monsters". chimerical combines the implication of visionary and fantastic "chimerical dreams of future progress". quixotic implies a devotion to romantic or chivalrous ideals unrestrained by ordinary prudence and common sense "a quixotic crusade".