Etymology of Odd and Even

Date: 10/08/2002 at 10:11:31
From: Tom Ray
Subject: Odd/even numbers

Why are odd numbers named "odd" and even numbers named "even"?

Date: 10/08/2002 at 10:30:09
From: Doctor Sarah
Subject: Re: Odd/even numbers

Hi Tom - thanks for writing to Dr. Math.

Here's what Steven Schwartzman has to say in his book, _The Words of 
Mathematics_ (Mathematical Association of America):

   even (adjective)...: a native English word with 
   cognates in other Germanic languages. Even means 
   "level, having no variation." A whole number is even 
   if it can be divided into two "level" or "uniform" 
   amounts. For example, 8 pennies can be divided into 
   two even (level) stacks of 4, whereas with an odd 
   number of pennies like 7 the two stacks are 
   necessarily uneven and don't reach the same level....

   odd (adjective)...: from Old Norse oddi, which referred 
   to pointy or uneven things, including triangles. 
   What distinguishes a triangle from a line is the odd 
   (= third) point "sticking out." For that reason a 
   person who stands out from the norm or who is strange 
   or unusual is called odd. An odd sock is one left over 
   after you've paired up your other socks, and so odd 
   came to refer to a number that is one greater than a 
   pair, i.e., one greater than an even number....

- Doctor Sarah, The Math Forum
  http://mathforum.org/dr.math/