Definition of hot foil in US English:

hot foil

adjective

Printing
  • Designating printing machines and processes in which a thin layer of material (typically metal or plastic) is transferred to a surface by being stamped or pressed on to it using a heated die.

noun

Printing
  • A thin layer of material used to produce an image, hologram, etc., in hot foil printing.

Origin

1950s; earliest use found in The Times.