adj. fearless
adv. fearlessly
n. fearlessness
v. to make or become fearless

Do not be afraid. Faasnu. Let me feel the power of your Thu'um.
(Paarthurnax, 000559DE)

Het mah faasnu ronaan Undveld, aar, kriid grohiik, ahrk drog do Lot Nir.
Here fell the fearless archer Undveld, servant, slayer of wolves, and lord of the Great Hunt.
(Word Wall for Nir, Aura Whisper)

Connotes bravery, disregarding what may be perceived by others as a threat or danger.

Faas ‘fear’ with the suffix -nu.