1. A shout to attract attention
   "he gave a great halloo but no one heard him"

1. Shout 'halloo', as when greeting someone or attracting attention
   "The hiker hallood to his lost companion"
    
2. Urge on with shouts
   "halloo the dogs in a hunt"

Derived forms: hallooing, halloos, hallooed

Type of: call, cry, egg, egg on, holler [informal], hollo [non-standard], incite, outcry, prod, scream, shout, shout out, squall, vociferation, yell

Encyclopedia: Halloo