While the first humbucker pickup in use, and issued a patent, was actually the Gretsch Filter'Tron pickup prototypes, designed by Ray Butts in 1954 at the request of Chet Atkins for his Gretsch 6120. The strange name of the pickup was not intentional.
2. uncountable noun. The division of something among people or things is its separation into parts which are distributed among the people or things. The current division of labor between workers and management will alter.
1 The act of differentiating.  The act of distinguishing or describing a thing, by giving its different, or specific difference; exact definition or determination.