To speak or say very loudly or with a shout
A loud cry
Find yourself another sitter to boss and holler at!
If I holler, fan out and make a circle.
The swim-bit is a hoot and a holler.
Nothing is better than a hysterical card that makes everyone hoot, holler and scream in delight as it is read to all the guests.
All you had to do was holler.