Fixed Income Clearing Corporation (FICC)
  
See: DTCC.
Fixed Income Clearing Corporation is one of those names that completely and blandly describes an organization, like the United States of America (USA) or the Organization of Lonely Bird Watchers Who Secretly Wish They Were Doing Anything Else Besides Watching Birds (OLBWWSWTWDAEBWB).
Let's break down the obvious name that makes up the FICC. Fixed income investments consist of securities that provide a fixed return...bonds, mostly. Clearing includes all the activities it takes to close a transaction...the boring "i" dotting and "t" crossing that goes on behind the scenes when you click "execute" on your trading platform.
So the Fixed Income Clearing Corporation is a corporation that provides clearing for fixed income securities. Treasury-and-mortgage-backed securities represent examples of its main business lines.
The company itself formed in 2003 through the merger of the Mortgage-Backed Security Clearing Corporation (MBSCC) and the Government Securities Clearing Corporation (GSCC).