Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
undaunted [ʌnˈdɔːntɪd] adj (person) неустраши́мый/неустраши́м
undaunted, she struggled on она́ неустраши́мо продолжа́ла свои́ стара́ния
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.