in Greek mythology, a queen of Thebes, daughter of Tantalus, married to Amphion, she was changed to a stone while weeping for her numerous children (slain, after she boasted of them overmuch, by Artemis and Apollo); hence the name is used figuratively for bereavement and woe. The name is said to mean literally "snowy; snowy-bright." By scientists the name was given to a type of trilobites and an asteroid. Related: Niobean.

Others are reading

Definitions of Niobe from WordNet

Niobe (n.)
(Greek mythology) the daughter of Tantalus whose boasting about her children provoked Apollo and Artemis to slay them all; Niobe was turned to stone while bewailing her loss;