blatancy

Etymology
Formed by analogy with the way that words that end in that are derived from French typically form their noun forms. This is erroneous logic in this case, however, because does not derive in any way from French, but is rather a native English formation using native English word parts ( and ), that only later had its ending slightly modified to fit more with other words that were more commonly used, that happened to have the French-derived  suffix.

Some other examples of the suffix changing to  over time are  and.

Noun

 * 1)  The state or quality of being blatant.