noun
: any of a group of rare-earth metals separable as a group from other metals occurring with them and in addition to terbium including europium, gadolinium, and sometimes dysprosium — compare yttrium metal
noun
: any of a group of rare-earth metals separable as a group from other metals occurring with them and in addition to terbium including europium, gadolinium, and sometimes dysprosium — compare yttrium metal
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012