List of Abstract Nouns: o

1. obtuse angle An abstract concept of a geometric feature that is the angle formed by two lines is larger than a right angle and is greater than 90 degree.last updated 4/16/2015
   http://en.wikipedia.org/wiki/Angle#Types_of_angles last updated 4/16/2015
2. oddity
3. oral An abstract concept of a two dimensional geometric figure that is a plane shape bounded by one single line with a rounded and slightly elongated like an egg of no well-defined or precise mathematical definition.last updated 4/16/2015
   http://en.wikipedia.org/wiki/Oval last updated 4/16/2015