noun
black rhinoceros
Refers to the species Diceros bicornis. Typically written in katakana as is common for animal names.
クロサイは絶滅危惧種に指定されている。
The black rhinoceros is designated as an endangered species.
White rhinoceros (Ceratotherium simum); a different species with a square lip, while the black rhino has a pointed lip.
Compound of 黒 (kuro, 'black') + 犀 (sai, 'rhinoceros'). The katakana spelling クロサイ is standard for animal names.