n 1 a : a surface that contains at least three points not all in a straight line and is such that a line drawn through any two points in it lies wholly in the surface b : an imaginary plane used to identify parts of the body or a part of the skull - see FRANKFORT HORIZONTAL PLANE MIDSAGITTAL PLANE 2 : a stage in surgical anesthesia <a light of anesthesia is maintained with cyclopropane -Jour. Amer. Med. Assoc.> .
Similar sounding terms: plana pla·no pol·len py·lon
Published under license with Merriam-Webster, Incorporated. © 1997-2004.