ivory nut

Từ điển WordNet v3.1 - WordNet Dictionary

noun

nutlike seed of a South American palm;
the hard white shell takes a high polish and is used for e.g. buttons
• Syn:
vegetable ivory, apple nut
• Hypernyms:
seed
• Part Holonyms:
ivory palm, ivory-nut palm, ivory plant, Phytelephas macrocarpa