Definition of mat leave in US English:

mat leave

noun

informal
  • A period of absence from work granted to a mother before and after the birth of her child.

    ‘the mat leave is very generous’
    ‘the plan is for Ann to go on mat leave’

Origin

1940s: shortening of maternity leave.

Pronunciation

mat leave

/ˈmat ˌlēv//ˈmæt ˌliv/