Translation

karibū means "Caribou" in English.
It's a katakanization, a loan-word.

karibū is normally written with katakana, as カリブー.
karibū written with hiragana is かりぶー.
karibū does not have kanji.
Romaji ka ri buu
Katakana
Hiragana

Orthography Notes

Trivia

Synonyms

Scientific name: Rangifer tarandus.

Further Reading

Wikipedia: トナカイ (Reindeer)