(n) In law or other industries where time is entered by professionals for billing to clients, the process by which the time is "written down," by owners of the firm to reduce the compensation of the professionals entering the time.
Frequently, this phenomenon is accompanied by the owners of the firm "writing up" their own time on the same file to increase their own share of the billings to the client.
I billed 200 hours last month, but the backfield shrinkage will probably cut that in half by the time that it gets billed out.
(verb) using a Black person as a shield to present/signal an image of diversity. Often used by companies to signal diversity in the workplace, or by individuals to signal that they're not racist.
1. That company was totally blackshielding behind their only Black executive who just so happens to be the Chief Diversity Officer.