daddy longlegsEnglishOxford New American Dictionarydaddy longlegs /ˌdadēˈlôNGleɡz, , ˌdædiˈlɔŋlɛɡz , ˌdadēˈläNGleɡz, ˌdædiˈlɑŋlɛɡz / ▸ noun (plural same) 1 North American an arachnid with a globular body and long thin legs, typically living in leaf litter and on tree trunks. Also called harvestman. Order Phalangida: numerous genera and species, including the common Phalangium opilio. 2 British a crane fly.