Translation

The Japanese word for "Ferret" is feretto フェレット, a katakanization.
Another word for "Ferret" is shiro-itachi 白鼬.

Romaji fe re tto
Katakanaフェレット
Hiraganaふぇれっと
Romaji shi ro i ta chi
Hiraganaしろいたち
Katakanaシロイタチ
Kanji 白 鼬
Meaning White Weasel
School Level 小1 ✕

Synonyms

Mustela putorius furo.

Further Reading

Wikipedia: Ferret (フェレット)