In general, the dit name is an addition used to differentiate one family from another with the same name. It can also be added for landed/titled persons. In the Fugère clan we have several:
Fugère dit Champagne - Edmé's line, Champagne added to differentiate him from Pierre's family
Fugère dit Aunis - Louis's line, Aunis added to differentiate him from Pierre and Edmé
Dit names can also be pronunciation variation or changes:
Fugère dit Fisher for the line of Fugères that moved to MI and adopted a phonetically similar variant.
Tonight I ran across a new one!
A set of Fugère brothers moved from Champlain, QC to Belknap county, NH and adopted Brake as their surname. Brake is a literal translation of 'fougere.' Generally it means fern, but can also be used for fernery, bracken, or brake.
I happened across this variant while searching records on Mocavo. One marriage record just happened to list both Fugere and Brake and I couldn't figure out why :)