noun
Common loanword used in compound nouns (e.g., モンキーレンチ, モンキーパーク) and in casual or brand contexts. For the animal in everyday speech, 猿 (さる) is more common.
その遊園地にはモンキーショーがある。
That amusement park has a monkey show.
彼はモンキーレンチでボルトを締めた。
He tightened the bolt with a monkey wrench.
猿 is the native Japanese word for monkey and is used in everyday speech. モンキー is a loanword often used in compound terms, brand names, or to give a casual/modern feel.
Borrowed from English 'monkey'.