liquid lunch
US /ˈlɪk.wɪd ˌlʌntʃ/
UK /ˈlɪk.wɪd ˌlʌntʃ/

1.
an alcoholic drink or drinks consumed instead of a meal, especially at lunchtime
:
•
He often has a liquid lunch on Fridays.
•
My boss is out for a liquid lunch, so he won't be back until late.