| Noun | 1. | halloo - a shout to attract attention; "he gave a great halloo but no one heard him"cry, outcry, shout, vociferation, yell, call - a loud utterance; often in protest or opposition; "the speaker was interrupted by loud cries from the rear of the audience" | |
| Verb | 1. | halloo - urge on with shouts; "halloo the dogs in a hunt"egg on, prod, incite - urge on; cause to act; "They other children egged the boy on, but he did not want to throw the stone through the window" | |
| 2. | halloo - shout `halloo', as when greeting someone or attracting attention | |