ODD--John Ayto in his book Dictionary of Word Origins, covers odd. according to him>>
The etymological idea underlying odd is of 'pointing upward'. Its ultimate ancestero is a prehistoric I-E *uzdho, a compound form of *uz (up) an *dho (put, place) (source, of the english Do).

From the notion of pointed vertical object, developed triangle, which in turn introduced the idea of three, and one left over from 2, hencem 'indivisible by 2" this was the meaning odd had when English borrowed it from old norse oddi, and the modern sense of 'peculiar' (as in the odd one out) did not emerge till the late 16th century.

(i change some of the detail--ie, i made (parens), that he had in italics, and used more (parens).. i didn't change the words!)


my other obsession