Synonyms for Daddy Longlegs (same or very similar meaning)
WordNet sense 1 (long-legged slender flies that resemble large mosquitoes but do not bite):
crane flyWordNet sense 2 (spiderlike arachnid with a small rounded body and very long thin legs):
harvestman, Phalangium opilioFrom the ODE community, based on WordNetadd/edit