Intrepidity refers to toughness and bravery. We hear a lot about heroism and courage in the news, sometimes in places far away from our homes. Intrepid behavior can be anyone's to own, though. It just means that you go out there without trepidation - or fear - and do whatever right thing needs to be done.
From Jonathan Swift's Gulliver's Travels, published in the 18th century:
However, in my thoughts I could not sufficiently wonder at the intrepidity of these diminutive mortals, who durst venture to mount and walk upon my body, while one of my hands was at liberty, without trembling at the very sight of so prodigious a creature as I must appear to them.
Durst is something similar to intrepidity, with an edge. Durst is an old word for "dare."
And what might prodigious mean in this passage? Does big in size or nature seem to fit? To the Lilliputian population, Gulliver may have seemed monstrously large!