CC is always Clear Channel the company, and not "clear channel" as in a class A clear channel AM station.
"The 5 C's" are Cumulus, Clear Channel, CBS, Cox, and Citadel.
AOR: Album Oriented Rock--rock that's harder than pop and focuses on album cuts and not necessarily singles. Used to refer to a distinct format and now is a catchall term for various album rock formats such as alternative, classic rock, active rock, etc.
BM: Beautiful Music--easy-listening instrumentals like what Muzak used to be known for.
MOR: Middle-of-the-road, not really used anymore to refer to light pop stations except historically
CHR can be subdivided into CHR/M (mainstream) or CHR/R (rhythmic)
R1: Radio One
AAA or Triple-A: Adult Album Alternative (cross between AC and alternative AOR)
TSL: Time Spent Listening-metric that tracks how long people listen to a rated station