Webster 1913 Edition
Being in the middle; running through the middle;
Situated in the middle; lying in a plane dividing a bilateral animal into right and left halves; – said of unpaired organs and parts;
Any line in the mesial plane; specif., either of the lines in which the mesial plane meets the surface of the body.
The line drawn from an angle of a triangle to the middle of the opposite side; any line having the nature of a diameter.–
the mesial plane.–
the point where the three median lines of a triangle mutually intersect.
A median line or point.