I'll share.
When I first considered the question, I thought back to when I was living in fear all the damn time... I am no longer living like that, and so when I compared that to how I am living now, I felt free. So, for me, the word opposite of fear is:
Freedom
Of course I can think of other words/feelings that work (for me) , but I keep circling back to my initial reaction. I'm quite content to own this feeling of freedom I have now as opposed to that daunting fear I was stifled with just a few short years ago. I feel free to choose to feel whatever I want to feel these days, and that is a blessing I don't think I can put into words.
What an awesome exercise! Thanks Fire!