Meaning

4 senses
  1. (US, colloquial)Someone who tells the truth.

  2. (US, colloquial)Someone who believes that the US government was responsible for the 9/11 attacks.

  3. (broadly)A conspiracy theorist who does not believe the accepted story about some significant event, fact, etc.

  4. (humorous, slang)An advocate, especially for a headcanon.

Origin

From truth + -er (occupational suffix) or + -er (“supporter”). For sense 2, directly from

From truth + -er (occupational suffix) or + -er (“supporter”). For sense 2, directly from name of the 9/11 Truth movement.

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