Noun.

Definition: The process or work of writing, editing, or compiling a dictionary.

http://www.thefreedictionary.com/lexicographical

I encountered this word while reading “Texting Shorthand Annoys Purists and May Have Lasting Impact” by Seth Mydans. Page 1, paragraph #3

I now understand that the person he was speaking about was trying to change the spelling of the english language.