Main definitions of millionaire's shortbread in US English:

: millionaire's shortbread1millionaire's shortbread2

millionaire's shortbread1

(also millionaire shortbread)

noun

  • Shortbread covered with a layer of caramel and topped with chocolate.

    ‘the base of the millionaire's shortbread wasn't great’

Main definitions of millionaire's shortbread in US English:

: millionaire's shortbread1millionaire's shortbread2

millionaire's shortbread2

noun

Scottish
  • Shortbread covered with a layer of caramel and topped with chocolate, typically served cut into small squares.

Origin

1990s.