devocalize or devocalise /dē-vōˈkə-līz/ or devoice /dē-voisˈ/

To make voiceless

• firebrands
• firebrat
• firebrats
• firebreak
• heterotaxies
• heterotaxis
• heterotaxy
• heterothallic
• heterothallies
• heterothallism
• heterothallisms
• heterothally
• heterothermal
• heterotic
• heterotopia
• heterotopias
• heterotopic
• heterotroph
• heterotrophic
• heterotrophies
• heterotrophs
• heterotrophy
• heterotypic
• heterousian
• heterousians