Used as a countable noun meaning the act or setting of removing frost/thawing.
Definitions
The process or act of removing frost or thawing something frozen, or the appliance setting that performs this function. Set the microwave to defrost before heating the frozen soup.
Attributive use describing devices/settings related to removing frost.
Definitions
Designed to remove frost or thaw frozen items. Press the defrost button to clear the rear window.