Acronym vs Initialism

The difference between acronyms and initialisms, inspired by Brooklyn Nine-Nine.

Published May 8, 2024 ET

Season 7, Episode 9 of Brooklyn Nine-Nine -- During the cold open, Captain Holt confuses an acronym with an initialism. Here's a Reddit post talking about it.

In both cases, the first letters from a series of words are put together, such as:

  • IRS for "Internal Revenue Service"
  • TNT for "trinitrotoluene"
  • LASER for "light amplification by stimulated emission of radiation"

The difference: With an acronym you pronounce the letters as their own word, and an initialism you pronounce the letters individually.

  • TNT and IRS are each an initialism
  • LASER is an acronym