depreciate

verb3

1. •
   To lessen in price or estimated value; to lower the worth of.

   • […] which […] some over-severe philosophers may look upon fastidiously, or undervalue and depreciate. — 1678
2. •
   To decline in value over time.
3. •
   To belittle or disparage.

   • They depreciated him because he was the youngest on the team.