elongation

Short definition from Wiktionary

Noun

1. 1
   The act of lengthening.
2. 2
   The state of being lengthened.
3. 3
   That which lengthens out; a continuation.
4. 4
   The ratio of the extension of a material to the length of the material prior to stretching.
5. 5
   A removal to a distance; a withdrawal; a being at a distance; a distance.
6. 6
   The angular distance of a planet from the sun.