'Imaginary quantity' definitions:

Definition of 'Imaginary quantity'

From: GCIDE
  • Imaginary \Im*ag"i*na*ry\, a. [L. imaginarius: cf. F. imaginaire.] Existing only in imagination or fancy; not real; fancied; visionary; ideal. [1913 Webster]
  • Wilt thou add to all the griefs I suffer Imaginary ills and fancied tortures? --Addison. [1913 Webster]
  • Imaginary calculus See under Calculus.
  • Imaginary expression or Imaginary quantity (Alg.), an algebraic expression which involves the impossible operation of taking the square root of a negative quantity; as, [root]-9, a + b [root]-1.
  • Imaginary points, lines, surfaces, etc. (Geom.), points, lines, surfaces, etc., imagined to exist, although by reason of certain changes of a figure they have in fact ceased to have a real existence.
  • Syn: Ideal; fanciful; chimerical; visionary; fancied; unreal; illusive. [1913 Webster]