[aw-toh toon, ‐tyoon]
  1. the proprietary name of a brand of software that processes vocal or instrumental tracks in a recording to correct pitch and timing errors.
verb (used with object)
  1. (sometimes lowercase) to alter (recorded audio) to correct pitch and timing or create a melody. Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for auto-tune

Contemporary Examples of auto-tune