umbo
/ˈʌmbəʊ/noun
(pl. umbones /ʌmˈbəʊniːz/ 或umbos)
1
- historical the central boss of a shield〈史〉盾心的浮雕装饰。
2
- Biology a rounded knob or protuberance【生】凸饰; 隆起物。
2.1
- Zoology the highest point of each valve of a bivalve shell【动】（双壳贝的）壳顶。
2.2
- Botany a central swelling on the cap of a mushroom or toadstool【植】（菌盖）中心突起
派生词
umbonal
adjective （chiefly Zoology 【主动】）umbonate
adjective （chiefly Botany 【主植】）词源
early 18th cent.: from Latin, 'shield boss'.