The One who is most fearsome.
The One who is the most Ugra.
To the one who shows the mildest laxity in Dharma or Dharmic exercise, she is the most fearsome. Her name is such that even KaliYuga’s impact is reduced for he who is her bhakta, for even KaliYuga does not dare invoke her rage.
Maa is who supports all of existence. She is the shakti, who will support all life. Her manifestations of various cosmic worlds, ethereal beings, ethereal planes, Gods and Goddesses and Deities, will support not only Her world of Maya but also the Sadhak, who is striving to go beyond all illusions.
Hence the name Daruna.