Translation

kawa-uso means "Otter" in English.

kawa-uso is normally written with katakana, as カワウソ.
kawa-uso written with hiragana is かわうそ.
kawa-uso written with kanji is 川獺.
This word contains non-jouyou kanji 常用漢字.
Romaji ka wa u so
Hiragana
Katakana
Kanji
Meaning River Otter
School Level 小1

kawa-uso may also be written as or 河獺.

Synonyms

ottā オッター, uso , oso , datsu , Lutrinae.

Further Reading

Wikipedia: (Otter)