Neigh v. i. : To utter the cry of the horse; to whinny.

Neigh v. i. : To scoff or sneer; to jeer.

Neigh n. : The cry of a horse; a whinny.

Example:
How to make a trumpet Neigh like a horse?

Taxonomy
Merriam-Webster Online Dictionary, Dictionary, webster, Word Games, Webster Online Dictionary with audio pronunciations, thesaurus, Middle English, Old English, Google Search, Custom Search, glossary, english, language, ESL, Search, intransitive verb, Etymology, neyen.

Defination from the web:
neigh from the Merriam-Webster Online Dictionary with audio pronunciations, thesaurus, Word of the Day, and word games. ... neyen, from Old English hnǣgan; akin to Middle High German nēgen to neigh. Date: before 12th century : to make the prolonged cry of a horse ...