Bebaak is the Urdu lafz used to describe something or someone fearless or bold.

Here are some couplets, the first by Mirza Ghalib and the second by Allama Iqbal that uses this lafz:

GHALIB SITRone se aur ishq mein bebaak ho gaye
Dhoye gaye hum itne ki bas paak ho gaye

I wept so much in love, that it made me fearless
I was washed so much, that I became pure

Dil soz se khali hai nigah paak nahin haiAllama-Iqbal
Phir is mein ajab kya ki tu bebaak nahin hai

The heart is empty of passion, the glance is impure
It is no wonder that you are not fearless any more