View full lesson: http://ed.ted.com/lessons/mysteries-of-vernacular-odd-jessica-oreck-and-rachael-teel

Whether we're talking all things unusual or mathematical, the origins of the word odd point to the Indo-European root uzdho, which means pointing upwards. Jessica Oreck and Rachael Teel explain the evolution from the term for a triangle to a number indivisible by two and, eventually, to the peculiar.

Lesson by Jessica Oreck and Rachael Teel, animation by Jessica Oreck.