Definition of "subsonic" [subsonic]

• Of less than audible frequency. (adjective)
• Having a speed less than that of sound in a designated medium. (adjective)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "There are others however, that are on a par with the Winchester Ranger 147-grain subsonic, and these are the CCI Speer Gold Dot and the Federal HST."
• "There are standard pressure loads, so-called "subsonic" loads, and ultra fast, high pressure, +P and +P+ loads."
• "(I can't give an actual number as I have not kept track, but I was just dying for a place to use the word "subsonic" somewhere in this column."