to utter a sudden loud cry
Aus, NZ, informal to buy a round of drinks
to utter (something) in a loud voice
Aus, NZ, informal to buy something, esp a drink, for (another person)
Aus, NZ, informal to buy (something, esp a drink) for somebody else
I dropped in to see if you'd shout an old friend a drink
shouter noun
shouty adj
[Middle English shouten, of Germanic origin]