Translation

gerenuku means "Gerenuk" in English.
It's a katakanization, a loan-word.

gerenuku is normally written with katakana, as ゲレヌク.
gerenuku written with hiragana is げれぬく.
gerenuku does not have kanji.
Romaji ge re nu ku
Katakana
Hiragana

Further Reading

Wikipedia: ジェレヌク (Gerenuk)