Webster's Revised Unabridged Dictionary · 1913

Neigh

Neigh (nā) , intransitive verb

[Old English neien, Anglo-Saxon hnagan, prob. of imitative origin; compare Middle High German nēgen, Icelandic hneggja, gneggja, Swedish gnagga. Compare Nag a horse.]

1.
To utter the cry of the horse; to whinny.
2.
To scoff or sneer; to jeer. [Obsolete]
Neighed at his nakedness. — Beau. & Fl

Neigh , noun

The cry of a horse; a whinny.