Whickered is a word that refers to the neighing sound made by a horse. There are several synonyms for this word. One of the most commonly used synonyms is "neighed." This word is used to describe the sound that a horse makes when it is excited or calling out to other horses. Another synonym for whickered is "nickered." This word is often used to describe the soft, low-pitched sound that a horse makes when it is communicating with other horses or its rider. Other synonyms for whickered include "snorted," "whinnied," and "brayed." Each of these words can be used to describe the unique vocalizations made by horses, depending on the context in which they are used.