Definition of "vertex" []

• The highest point; the apex or summit: the vertex of a mountain. (noun)
• Anatomy The highest point of the skull. (noun)
• Anatomy The top of the head. (noun)
• Astronomy The highest point reached in the apparent motion of a celestial body. (noun)
• Mathematics The point at which the sides of an angle intersect. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "Thus: what we call the vertex of the Brain is really its base and what we call its base is really its vertex, it is simply a question of nomenclature."
• "Thus the interior angle at each vertex is either 90° or 270°."
• ""What we call the vertex of the Brain is really its base: and what we call its base is really its vertex: it is simply a question of nomenclature.""