Real Dictionary

Niobe in American English
a queen of Thebes, daughter of Tantalus, who, weeping for her slain children, is turned into a stone from which tears continue to flow
noun: the daughter of Tantalus and wife of Amphion of Thebes. She provoked Apollo and Artemis to vengeance by taunting their mother, Leto, with the number and beauty of her own children; Niobe's children were slain and Zeus turned her into stone, in which state

Niobe in British English
noun: a daughter of Tantalus, whose children were slain after she boasted of them: although turned into stone, she continued to weep