sunbirdPronunciation: /ˈsʌnbəːd/Definition of sunbird noun a small, brightly coloured Old World songbird with a long downcurved bill, feeding on nectar and resembling a hummingbird (but not able to hover). Family Nectariniidae: four genera, in particular Nectarinia, and numerous species sunbird in other Oxford dictionaries Definition of sunbird in the US English dictionary