What is the meaning of holler?

noun

• A very loud utterance (like the sound of an animal. )
  • usage: "his bellow filled the hallway"
  • synonyms: bellow, bellowing, holla, hollering, hollo, holloa, roar, roaring, yowl
• A small valley between mountains.
  • usage: "he built himself a cabin in a hollow high up in the Appalachians"
  • synonyms: hollow

verb

• Shout out.
  • usage: "He hollered out to surrender our weapons"
  • synonyms: holler out
• Utter a sudden loud cry.
  • usage: "she cried with pain when the doctor inserted the needle"; "I yelled to her from the window but she couldn't hear me"
  • synonyms: shout, shout out, cry, call, yell, scream, hollo, squall
• Complain.
  • usage: "What was he hollering about"
  • synonyms: gripe, bitch, grouse, crab, beef, squawk, bellyache