ponytail ponytail /ˈpəʊ.ni.teɪl/ aep /ˈpoʊ.ni.teɪl/ noun [C] ► F0 a hairstyle in which the hair is tied up high at the back of the head so that it hangs down like a horse's tail→COMPAREPIGTAIL(Cf. ↑pigtail), PLAIT(Cf. ↑plait) verbThesaurus+: ↑Hairstyles