1. present participle of hulloo; shouting 'hullo' or 'hello' to attract attention or greet someone
Usage: informal; chiefly British
2. shouting or calling out loudly, especially to urge on hunting dogs or to make noise
Usage: informal; archaic

Examples

• She was hullooing across the field to get her friend's attention.
• The hunters were hullooing to encourage their dogs during the chase.
• He stood on the hill, hullooing until someone finally heard him.
• They spent the afternoon hullooing and waving at the passing boats.
• The children were hullooing excitedly when they spotted the parade.