Gelding – A castrated equine animal such as a horse or a donkey
(Pronounced gel-ding (first syllable has a hard "g" as in "go"))
The girl held the prancing (gelding) horse tightly by the reins - it was nervous because it sensed it was about to be castrated.
Examples of gelding in a sentence
The bay gelding was much calmer than the chestnut mare.
Even though the racehorse was now a gelding, it didn't effect his racing results.
My horse is a 16.1 grey gelding, he's very easy to ride and his favourite treats are carrots.