- Zoology. the median plane of the body of an animal.
- Geometry. midsegment.
Origin of midline
Examples from the Web for midline
Historical Examples of midline
Ventrally, the new adult pelage was evident only along the midline.Mammals of Northwestern South Dakota
Kenneth W. Andersen
The remaining anterior edge is slightly convex, smoothly rounded, and meets the midline about 9.0 mm.A New Order of Fishlike Amphibia From the Pennsylvanian of Kansas
Theodore H. Eaton
These areas may or may not be connected by a thin line of white color along the midline of the underparts.American Weasels
E. Raymond Hall
The red tips tend further to disrupt the body outline at the midline, or slightly posterior to this.Phylogeny of the Waxwings and Allied Birds
M. Dale Arvey
The single blowhole is located well to the left of the midline and far forward on the head.Whales, Dolphins, and Porpoises of the Western North Atlantic
- A medial line, especially the medial line or plane of the body.